diff --git a/bin/typescript-angular-v4.3-petstore-with-npm.sh b/bin/typescript-angular-v4.3-petstore-with-npm.sh
old mode 100644
new mode 100755
diff --git a/bin/windows/typescript-angular-v4.3-with-npm.bat b/bin/windows/typescript-angular-v4.3-with-npm.bat
new file mode 100644
index 00000000000..5ad1cbd9b2d
--- /dev/null
+++ b/bin/windows/typescript-angular-v4.3-with-npm.bat
@@ -0,0 +1,10 @@
+set executable=.\modules\swagger-codegen-cli\target\swagger-codegen-cli.jar
+
+If Not Exist %executable% (
+  mvn clean package
+)
+
+REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M
+set ags=generate -i modules\swagger-codegen\src\test\resources\2_0\petstore.yaml -c bin\typescript-petstore-npm.json -l typescript-angular -o samples\client\petstore\typescript-angular-v4.3\npm --additional-properties ngVersion=4.3
+
+java %JAVA_OPTS% -jar %executable% %ags%
diff --git a/modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache b/modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache
index 56e0e67dce8..ea2b19b7885 100644
--- a/modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache
+++ b/modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache
@@ -20,7 +20,12 @@ import { {{classname}} } from '../{{filename}}';
 
 import { BASE_PATH, COLLECTION_FORMATS }                     from '../variables';
 import { Configuration }                                     from '../configuration';
+{{#useHttpClient}}
+import { CustomHttpUrlEncodingCodec }                        from '../encoder';
+{{/useHttpClient}}
+{{^useHttpClient}}
 import { CustomQueryEncoderHelper }                          from '../encoder';
+{{/useHttpClient}}
 {{#withInterfaces}}
 import { {{classname}}Interface }                            from './{{classname}}Interface';
 {{/withInterfaces}}
@@ -69,11 +74,6 @@ export class {{classname}} {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
 {{^useHttpClient}}
 {{! not sure why we used to generate a second method here rather than inlining those few lines of code, 
     but let's keep it for now for the sake of backwards compatiblity. }}  
@@ -121,7 +121,12 @@ export class {{classname}} {
 {{/allParams}}
 
 {{#hasQueryParams}}
-        let queryParameters = new {{#useHttpClient}}HttpParams{{/useHttpClient}}{{^useHttpClient}}URLSearchParams{{/useHttpClient}}();
+        {{#useHttpClient}}
+        let queryParameters = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
+        {{/useHttpClient}}
+        {{^useHttpClient}}
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
+        {{/useHttpClient}}
 {{#queryParams}}
         {{#isListContainer}}
         if ({{paramName}}) {
@@ -207,39 +212,59 @@ export class {{classname}} {
             '{{{mediaType}}}'{{#hasMore}},{{/hasMore}}
             {{/consumes}}
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
 {{#formParams}}
 {{#isFile}}
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
 {{/isFile}}
 {{/formParams}}
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+{{#useHttpClient}}
+            formParams = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
+{{/useHttpClient}}
+{{^useHttpClient}}
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+{{/useHttpClient}}
+        }
+
+
+
 {{#formParams}}
         {{#isListContainer}}
         if ({{paramName}}) {
         {{#isCollectionFormatMulti}}
             {{paramName}}.forEach((element) => {
-                formParams.append('{{baseName}}', <any>element);
+                {{#useHttpClient}}formParams = {{/useHttpClient}}formParams.append('{{baseName}}', <any>element){{#useHttpClient}} || formParams{{/useHttpClient}};
             })
         {{/isCollectionFormatMulti}}
         {{^isCollectionFormatMulti}}
-            formParams.set('{{baseName}}', {{paramName}}.join(COLLECTION_FORMATS['{{collectionFormat}}']));
+            {{#useHttpClient}}formParams = {{/useHttpClient}}formParams.append('{{baseName}}', {{paramName}}.join(COLLECTION_FORMATS['{{collectionFormat}}'])){{#useHttpClient}} || formParams{{/useHttpClient}};
         {{/isCollectionFormatMulti}}
         }
         {{/isListContainer}}
         {{^isListContainer}}
         if ({{paramName}} !== undefined) {
-            formParams.set('{{baseName}}', <any>{{paramName}});
+            {{#useHttpClient}}formParams = {{/useHttpClient}}formParams.append('{{baseName}}', <any>{{paramName}}){{#useHttpClient}} || formParams{{/useHttpClient}};
         }
         {{/isListContainer}}
 {{/formParams}}
 
 {{/hasFormParams}}
 {{#useHttpClient}}
-        return this.httpClient.{{httpMethod}}{{^isResponseFile}}<any>{{/isResponseFile}}(`${this.basePath}{{{path}}}`, {{#bodyParam}}{{paramName}}, {{/bodyParam}}{{#hasFormParams}}formParams, {{/hasFormParams}}{
+        return this.httpClient.{{httpMethod}}{{^isResponseFile}}<any>{{/isResponseFile}}(`${this.basePath}{{{path}}}`, {{#bodyParam}}{{paramName}}, {{/bodyParam}}
+        {{#hasFormParams}}convertFormParamsToString ? formParams.toString() : formParams, {{/hasFormParams}}{
 {{#hasQueryParams}}
             params: queryParameters,
 {{/hasQueryParams}}
@@ -258,7 +283,7 @@ export class {{classname}} {
             body: {{paramName}} == null ? '' : JSON.stringify({{paramName}}), // https://github.com/angular/angular/issues/10612
 {{/bodyParam}}
 {{#hasFormParams}}
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
 {{/hasFormParams}}
 {{#isResponseFile}}
             responseType: ResponseContentType.Blob,
diff --git a/modules/swagger-codegen/src/main/resources/typescript-angular/encoder.mustache b/modules/swagger-codegen/src/main/resources/typescript-angular/encoder.mustache
index 319f79da15a..c3ac784124a 100644
--- a/modules/swagger-codegen/src/main/resources/typescript-angular/encoder.mustache
+++ b/modules/swagger-codegen/src/main/resources/typescript-angular/encoder.mustache
@@ -1,5 +1,28 @@
-import { QueryEncoder } from "@angular/http";
+{{#useHttpClient}}
+    import { HttpUrlEncodingCodec } from '@angular/common/http';
+{{/useHttpClient}}
+{{^useHttpClient}}
+    import { QueryEncoder } from '@angular/http';
+{{/useHttpClient}}
 
+{{#useHttpClient}}
+/**
+* CustomHttpUrlEncodingCodec
+* Fix plus sign (+) not encoding, so sent as blank space
+* See: https://github.com/angular/angular/issues/11058#issuecomment-247367318
+*/
+export class CustomHttpUrlEncodingCodec extends HttpUrlEncodingCodec {
+    encodeKey(k: string): string {
+        k = super.encodeKey(k);
+        return k.replace(/\+/gi, '%2B');
+    }
+    encodeValue(v: string): string {
+        v = super.encodeValue(v);
+        return v.replace(/\+/gi, '%2B');
+    }
+}
+{{/useHttpClient}}
+{{^useHttpClient}}
 /**
 * CustomQueryEncoderHelper
 * Fix plus sign (+) not encoding, so sent as blank space
@@ -14,4 +37,6 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+{{/useHttpClient}}
+
diff --git a/samples/client/petstore/typescript-angular-v2/default/api/pet.service.ts b/samples/client/petstore/typescript-angular-v2/default/api/pet.service.ts
index 481f693424e..11a1b603831 100644
--- a/samples/client/petstore/typescript-angular-v2/default/api/pet.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/default/api/pet.service.ts
@@ -60,11 +60,6 @@ export class PetService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * 
      * @summary Add a new pet to the store
@@ -282,7 +277,7 @@ export class PetService {
             throw new Error('Required parameter status was null or undefined when calling findPetsByStatus.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (status) {
             queryParameters.set('status', status.join(COLLECTION_FORMATS['csv']));
         }
@@ -321,7 +316,7 @@ export class PetService {
             throw new Error('Required parameter tags was null or undefined when calling findPetsByTags.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (tags) {
             queryParameters.set('tags', tags.join(COLLECTION_FORMATS['csv']));
         }
@@ -442,22 +437,34 @@ export class PetService {
         let consumes: string[] = [
             'application/x-www-form-urlencoded'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        let convertFormParamsToString = false;
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (name !== undefined) {
-            formParams.set('name', <any>name);
+            formParams.append('name', <any>name);
         }
         if (status !== undefined) {
-            formParams.set('status', <any>status);
+            formParams.append('status', <any>status);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
@@ -494,23 +501,37 @@ export class PetService {
         let consumes: string[] = [
             'multipart/form-data'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (additionalMetadata !== undefined) {
-            formParams.set('additionalMetadata', <any>additionalMetadata);
+            formParams.append('additionalMetadata', <any>additionalMetadata);
         }
         if (file !== undefined) {
-            formParams.set('file', <any>file);
+            formParams.append('file', <any>file);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
diff --git a/samples/client/petstore/typescript-angular-v2/default/api/store.service.ts b/samples/client/petstore/typescript-angular-v2/default/api/store.service.ts
index fba4c08d9aa..393d291ba3d 100644
--- a/samples/client/petstore/typescript-angular-v2/default/api/store.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/default/api/store.service.ts
@@ -59,11 +59,6 @@ export class StoreService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
      * @summary Delete purchase order by ID
diff --git a/samples/client/petstore/typescript-angular-v2/default/api/user.service.ts b/samples/client/petstore/typescript-angular-v2/default/api/user.service.ts
index d7c9ee1510a..f495f1f9d39 100644
--- a/samples/client/petstore/typescript-angular-v2/default/api/user.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/default/api/user.service.ts
@@ -59,11 +59,6 @@ export class UserService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * This can only be done by the logged in user.
      * @summary Create user
@@ -342,7 +337,7 @@ export class UserService {
             throw new Error('Required parameter password was null or undefined when calling loginUser.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (username !== undefined) {
             queryParameters.set('username', <any>username);
         }
diff --git a/samples/client/petstore/typescript-angular-v2/default/encoder.ts b/samples/client/petstore/typescript-angular-v2/default/encoder.ts
index 319f79da15a..6fcda7b246d 100644
--- a/samples/client/petstore/typescript-angular-v2/default/encoder.ts
+++ b/samples/client/petstore/typescript-angular-v2/default/encoder.ts
@@ -1,4 +1,4 @@
-import { QueryEncoder } from "@angular/http";
+    import { QueryEncoder } from '@angular/http';
 
 /**
 * CustomQueryEncoderHelper
@@ -14,4 +14,5 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+
diff --git a/samples/client/petstore/typescript-angular-v2/npm/api/pet.service.ts b/samples/client/petstore/typescript-angular-v2/npm/api/pet.service.ts
index 481f693424e..11a1b603831 100644
--- a/samples/client/petstore/typescript-angular-v2/npm/api/pet.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/npm/api/pet.service.ts
@@ -60,11 +60,6 @@ export class PetService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * 
      * @summary Add a new pet to the store
@@ -282,7 +277,7 @@ export class PetService {
             throw new Error('Required parameter status was null or undefined when calling findPetsByStatus.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (status) {
             queryParameters.set('status', status.join(COLLECTION_FORMATS['csv']));
         }
@@ -321,7 +316,7 @@ export class PetService {
             throw new Error('Required parameter tags was null or undefined when calling findPetsByTags.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (tags) {
             queryParameters.set('tags', tags.join(COLLECTION_FORMATS['csv']));
         }
@@ -442,22 +437,34 @@ export class PetService {
         let consumes: string[] = [
             'application/x-www-form-urlencoded'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        let convertFormParamsToString = false;
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (name !== undefined) {
-            formParams.set('name', <any>name);
+            formParams.append('name', <any>name);
         }
         if (status !== undefined) {
-            formParams.set('status', <any>status);
+            formParams.append('status', <any>status);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
@@ -494,23 +501,37 @@ export class PetService {
         let consumes: string[] = [
             'multipart/form-data'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (additionalMetadata !== undefined) {
-            formParams.set('additionalMetadata', <any>additionalMetadata);
+            formParams.append('additionalMetadata', <any>additionalMetadata);
         }
         if (file !== undefined) {
-            formParams.set('file', <any>file);
+            formParams.append('file', <any>file);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
diff --git a/samples/client/petstore/typescript-angular-v2/npm/api/store.service.ts b/samples/client/petstore/typescript-angular-v2/npm/api/store.service.ts
index fba4c08d9aa..393d291ba3d 100644
--- a/samples/client/petstore/typescript-angular-v2/npm/api/store.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/npm/api/store.service.ts
@@ -59,11 +59,6 @@ export class StoreService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
      * @summary Delete purchase order by ID
diff --git a/samples/client/petstore/typescript-angular-v2/npm/api/user.service.ts b/samples/client/petstore/typescript-angular-v2/npm/api/user.service.ts
index d7c9ee1510a..f495f1f9d39 100644
--- a/samples/client/petstore/typescript-angular-v2/npm/api/user.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/npm/api/user.service.ts
@@ -59,11 +59,6 @@ export class UserService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * This can only be done by the logged in user.
      * @summary Create user
@@ -342,7 +337,7 @@ export class UserService {
             throw new Error('Required parameter password was null or undefined when calling loginUser.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (username !== undefined) {
             queryParameters.set('username', <any>username);
         }
diff --git a/samples/client/petstore/typescript-angular-v2/npm/encoder.ts b/samples/client/petstore/typescript-angular-v2/npm/encoder.ts
index 319f79da15a..6fcda7b246d 100644
--- a/samples/client/petstore/typescript-angular-v2/npm/encoder.ts
+++ b/samples/client/petstore/typescript-angular-v2/npm/encoder.ts
@@ -1,4 +1,4 @@
-import { QueryEncoder } from "@angular/http";
+    import { QueryEncoder } from '@angular/http';
 
 /**
 * CustomQueryEncoderHelper
@@ -14,4 +14,5 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+
diff --git a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/pet.service.ts b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/pet.service.ts
index b87a0bd2288..8ff5eda659d 100644
--- a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/pet.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/pet.service.ts
@@ -61,11 +61,6 @@ export class PetService implements PetServiceInterface {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * 
      * @summary Add a new pet to the store
@@ -283,7 +278,7 @@ export class PetService implements PetServiceInterface {
             throw new Error('Required parameter status was null or undefined when calling findPetsByStatus.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (status) {
             queryParameters.set('status', status.join(COLLECTION_FORMATS['csv']));
         }
@@ -322,7 +317,7 @@ export class PetService implements PetServiceInterface {
             throw new Error('Required parameter tags was null or undefined when calling findPetsByTags.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (tags) {
             queryParameters.set('tags', tags.join(COLLECTION_FORMATS['csv']));
         }
@@ -443,22 +438,34 @@ export class PetService implements PetServiceInterface {
         let consumes: string[] = [
             'application/x-www-form-urlencoded'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        let convertFormParamsToString = false;
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (name !== undefined) {
-            formParams.set('name', <any>name);
+            formParams.append('name', <any>name);
         }
         if (status !== undefined) {
-            formParams.set('status', <any>status);
+            formParams.append('status', <any>status);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
@@ -495,23 +502,37 @@ export class PetService implements PetServiceInterface {
         let consumes: string[] = [
             'multipart/form-data'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (additionalMetadata !== undefined) {
-            formParams.set('additionalMetadata', <any>additionalMetadata);
+            formParams.append('additionalMetadata', <any>additionalMetadata);
         }
         if (file !== undefined) {
-            formParams.set('file', <any>file);
+            formParams.append('file', <any>file);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
diff --git a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/store.service.ts b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/store.service.ts
index d5a468340c4..1297e638d43 100644
--- a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/store.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/store.service.ts
@@ -60,11 +60,6 @@ export class StoreService implements StoreServiceInterface {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
      * @summary Delete purchase order by ID
diff --git a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/user.service.ts b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/user.service.ts
index 3574e7f2c7e..480d00b3bb6 100644
--- a/samples/client/petstore/typescript-angular-v2/with-interfaces/api/user.service.ts
+++ b/samples/client/petstore/typescript-angular-v2/with-interfaces/api/user.service.ts
@@ -60,11 +60,6 @@ export class UserService implements UserServiceInterface {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * This can only be done by the logged in user.
      * @summary Create user
@@ -343,7 +338,7 @@ export class UserService implements UserServiceInterface {
             throw new Error('Required parameter password was null or undefined when calling loginUser.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (username !== undefined) {
             queryParameters.set('username', <any>username);
         }
diff --git a/samples/client/petstore/typescript-angular-v2/with-interfaces/encoder.ts b/samples/client/petstore/typescript-angular-v2/with-interfaces/encoder.ts
index 319f79da15a..6fcda7b246d 100644
--- a/samples/client/petstore/typescript-angular-v2/with-interfaces/encoder.ts
+++ b/samples/client/petstore/typescript-angular-v2/with-interfaces/encoder.ts
@@ -1,4 +1,4 @@
-import { QueryEncoder } from "@angular/http";
+    import { QueryEncoder } from '@angular/http';
 
 /**
 * CustomQueryEncoderHelper
@@ -14,4 +14,5 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+
diff --git a/samples/client/petstore/typescript-angular-v4.3/npm/api/pet.service.ts b/samples/client/petstore/typescript-angular-v4.3/npm/api/pet.service.ts
index 9e7e00d1e48..ee44df243de 100644
--- a/samples/client/petstore/typescript-angular-v4.3/npm/api/pet.service.ts
+++ b/samples/client/petstore/typescript-angular-v4.3/npm/api/pet.service.ts
@@ -23,7 +23,7 @@ import { Pet } from '../model/pet';
 
 import { BASE_PATH, COLLECTION_FORMATS }                     from '../variables';
 import { Configuration }                                     from '../configuration';
-import { CustomQueryEncoderHelper }                          from '../encoder';
+import { CustomHttpUrlEncodingCodec }                        from '../encoder';
 
 
 @Injectable()
@@ -58,6 +58,7 @@ export class PetService {
     }
 
 
+
     /**
      * Add a new pet to the store
      * 
@@ -78,7 +79,8 @@ export class PetService {
             headers = headers.set('Authorization', 'Bearer ' + accessToken);
         }
 
-        return this.httpClient.post<any>(`${this.basePath}/pet`, body, {
+        return this.httpClient.post<any>(`${this.basePath}/pet`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -108,7 +110,8 @@ export class PetService {
             headers = headers.set('Authorization', 'Bearer ' + accessToken);
         }
 
-        return this.httpClient.delete<any>(`${this.basePath}/pet/${encodeURIComponent(petId)}`, {
+        return this.httpClient.delete<any>(`${this.basePath}/pet/${encodeURIComponent(String(petId))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -124,7 +127,7 @@ export class PetService {
             throw new Error('Required parameter status was null or undefined when calling findPetsByStatus.');
         }
 
-        let queryParameters = new HttpParams();
+        let queryParameters = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
         if (status) {
             queryParameters = queryParameters.set('status', status.join(COLLECTION_FORMATS['csv']));
         }
@@ -139,7 +142,8 @@ export class PetService {
             headers = headers.set('Authorization', 'Bearer ' + accessToken);
         }
 
-        return this.httpClient.get<any>(`${this.basePath}/pet/findByStatus`, {
+        return this.httpClient.get<any>(`${this.basePath}/pet/findByStatus`, 
+        {
             params: queryParameters,
             headers: headers,
             withCredentials: this.configuration.withCredentials,
@@ -156,7 +160,7 @@ export class PetService {
             throw new Error('Required parameter tags was null or undefined when calling findPetsByTags.');
         }
 
-        let queryParameters = new HttpParams();
+        let queryParameters = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
         if (tags) {
             queryParameters = queryParameters.set('tags', tags.join(COLLECTION_FORMATS['csv']));
         }
@@ -171,7 +175,8 @@ export class PetService {
             headers = headers.set('Authorization', 'Bearer ' + accessToken);
         }
 
-        return this.httpClient.get<any>(`${this.basePath}/pet/findByTags`, {
+        return this.httpClient.get<any>(`${this.basePath}/pet/findByTags`, 
+        {
             params: queryParameters,
             headers: headers,
             withCredentials: this.configuration.withCredentials,
@@ -195,7 +200,8 @@ export class PetService {
             headers = headers.set('api_key', this.configuration.apiKeys["api_key"]);
         }
 
-        return this.httpClient.get<any>(`${this.basePath}/pet/${encodeURIComponent(petId)}`, {
+        return this.httpClient.get<any>(`${this.basePath}/pet/${encodeURIComponent(String(petId))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -221,7 +227,8 @@ export class PetService {
             headers = headers.set('Authorization', 'Bearer ' + accessToken);
         }
 
-        return this.httpClient.put<any>(`${this.basePath}/pet`, body, {
+        return this.httpClient.put<any>(`${this.basePath}/pet`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -253,19 +260,28 @@ export class PetService {
         let consumes: string[] = [
             'application/x-www-form-urlencoded'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        let convertFormParamsToString = false;
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            formParams = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
+        }
+
+
+
         if (name !== undefined) {
-            formParams.set('name', <any>name);
+            formParams = formParams.append('name', <any>name) || formParams;
         }
         if (status !== undefined) {
-            formParams.set('status', <any>status);
+            formParams = formParams.append('status', <any>status) || formParams;
         }
 
-        return this.httpClient.post<any>(`${this.basePath}/pet/${encodeURIComponent(petId)}`, formParams, {
+        return this.httpClient.post<any>(`${this.basePath}/pet/${encodeURIComponent(String(petId))}`, 
+        convertFormParamsToString ? formParams.toString() : formParams, {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -297,20 +313,31 @@ export class PetService {
         let consumes: string[] = [
             'multipart/form-data'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            formParams = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
+        }
+
+
+
         if (additionalMetadata !== undefined) {
-            formParams.set('additionalMetadata', <any>additionalMetadata);
+            formParams = formParams.append('additionalMetadata', <any>additionalMetadata) || formParams;
         }
         if (file !== undefined) {
-            formParams.set('file', <any>file);
+            formParams = formParams.append('file', <any>file) || formParams;
         }
 
-        return this.httpClient.post<any>(`${this.basePath}/pet/${encodeURIComponent(petId)}/uploadImage`, formParams, {
+        return this.httpClient.post<any>(`${this.basePath}/pet/${encodeURIComponent(String(petId))}/uploadImage`, 
+        convertFormParamsToString ? formParams.toString() : formParams, {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
diff --git a/samples/client/petstore/typescript-angular-v4.3/npm/api/store.service.ts b/samples/client/petstore/typescript-angular-v4.3/npm/api/store.service.ts
index e52b46095ce..f0cf7dbc1cb 100644
--- a/samples/client/petstore/typescript-angular-v4.3/npm/api/store.service.ts
+++ b/samples/client/petstore/typescript-angular-v4.3/npm/api/store.service.ts
@@ -22,7 +22,7 @@ import { Order } from '../model/order';
 
 import { BASE_PATH, COLLECTION_FORMATS }                     from '../variables';
 import { Configuration }                                     from '../configuration';
-import { CustomQueryEncoderHelper }                          from '../encoder';
+import { CustomHttpUrlEncodingCodec }                        from '../encoder';
 
 
 @Injectable()
@@ -57,6 +57,7 @@ export class StoreService {
     }
 
 
+
     /**
      * Delete purchase order by ID
      * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
@@ -69,7 +70,8 @@ export class StoreService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.delete<any>(`${this.basePath}/store/order/${encodeURIComponent(orderId)}`, {
+        return this.httpClient.delete<any>(`${this.basePath}/store/order/${encodeURIComponent(String(orderId))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -88,7 +90,8 @@ export class StoreService {
             headers = headers.set('api_key', this.configuration.apiKeys["api_key"]);
         }
 
-        return this.httpClient.get<any>(`${this.basePath}/store/inventory`, {
+        return this.httpClient.get<any>(`${this.basePath}/store/inventory`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -106,7 +109,8 @@ export class StoreService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.get<any>(`${this.basePath}/store/order/${encodeURIComponent(orderId)}`, {
+        return this.httpClient.get<any>(`${this.basePath}/store/order/${encodeURIComponent(String(orderId))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -124,7 +128,8 @@ export class StoreService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.post<any>(`${this.basePath}/store/order`, body, {
+        return this.httpClient.post<any>(`${this.basePath}/store/order`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
diff --git a/samples/client/petstore/typescript-angular-v4.3/npm/api/user.service.ts b/samples/client/petstore/typescript-angular-v4.3/npm/api/user.service.ts
index cc53d7367bc..d67fb448fc3 100644
--- a/samples/client/petstore/typescript-angular-v4.3/npm/api/user.service.ts
+++ b/samples/client/petstore/typescript-angular-v4.3/npm/api/user.service.ts
@@ -22,7 +22,7 @@ import { User } from '../model/user';
 
 import { BASE_PATH, COLLECTION_FORMATS }                     from '../variables';
 import { Configuration }                                     from '../configuration';
-import { CustomQueryEncoderHelper }                          from '../encoder';
+import { CustomHttpUrlEncodingCodec }                        from '../encoder';
 
 
 @Injectable()
@@ -57,6 +57,7 @@ export class UserService {
     }
 
 
+
     /**
      * Create user
      * This can only be done by the logged in user.
@@ -69,7 +70,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.post<any>(`${this.basePath}/user`, body, {
+        return this.httpClient.post<any>(`${this.basePath}/user`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -87,7 +89,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.post<any>(`${this.basePath}/user/createWithArray`, body, {
+        return this.httpClient.post<any>(`${this.basePath}/user/createWithArray`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -105,7 +108,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.post<any>(`${this.basePath}/user/createWithList`, body, {
+        return this.httpClient.post<any>(`${this.basePath}/user/createWithList`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -123,7 +127,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.delete<any>(`${this.basePath}/user/${encodeURIComponent(username)}`, {
+        return this.httpClient.delete<any>(`${this.basePath}/user/${encodeURIComponent(String(username))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -141,7 +146,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.get<any>(`${this.basePath}/user/${encodeURIComponent(username)}`, {
+        return this.httpClient.get<any>(`${this.basePath}/user/${encodeURIComponent(String(username))}`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -161,7 +167,7 @@ export class UserService {
             throw new Error('Required parameter password was null or undefined when calling loginUser.');
         }
 
-        let queryParameters = new HttpParams();
+        let queryParameters = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
         if (username !== undefined) {
             queryParameters = queryParameters.set('username', <any>username);
         }
@@ -171,7 +177,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.get<any>(`${this.basePath}/user/login`, {
+        return this.httpClient.get<any>(`${this.basePath}/user/login`, 
+        {
             params: queryParameters,
             headers: headers,
             withCredentials: this.configuration.withCredentials,
@@ -186,7 +193,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.get<any>(`${this.basePath}/user/logout`, {
+        return this.httpClient.get<any>(`${this.basePath}/user/logout`, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
@@ -208,7 +216,8 @@ export class UserService {
 
         let headers = this.defaultHeaders;
 
-        return this.httpClient.put<any>(`${this.basePath}/user/${encodeURIComponent(username)}`, body, {
+        return this.httpClient.put<any>(`${this.basePath}/user/${encodeURIComponent(String(username))}`, body, 
+        {
             headers: headers,
             withCredentials: this.configuration.withCredentials,
         });
diff --git a/samples/client/petstore/typescript-angular-v4.3/npm/encoder.ts b/samples/client/petstore/typescript-angular-v4.3/npm/encoder.ts
index 319f79da15a..f1c6b78c9c8 100644
--- a/samples/client/petstore/typescript-angular-v4.3/npm/encoder.ts
+++ b/samples/client/petstore/typescript-angular-v4.3/npm/encoder.ts
@@ -1,11 +1,11 @@
-import { QueryEncoder } from "@angular/http";
+    import { HttpUrlEncodingCodec } from '@angular/common/http';
 
 /**
-* CustomQueryEncoderHelper
+* CustomHttpUrlEncodingCodec
 * Fix plus sign (+) not encoding, so sent as blank space
 * See: https://github.com/angular/angular/issues/11058#issuecomment-247367318
 */
-export class CustomQueryEncoderHelper extends QueryEncoder {
+export class CustomHttpUrlEncodingCodec extends HttpUrlEncodingCodec {
     encodeKey(k: string): string {
         k = super.encodeKey(k);
         return k.replace(/\+/gi, '%2B');
@@ -14,4 +14,5 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+
diff --git a/samples/client/petstore/typescript-angular-v4/npm/api/pet.service.ts b/samples/client/petstore/typescript-angular-v4/npm/api/pet.service.ts
index 481f693424e..11a1b603831 100644
--- a/samples/client/petstore/typescript-angular-v4/npm/api/pet.service.ts
+++ b/samples/client/petstore/typescript-angular-v4/npm/api/pet.service.ts
@@ -60,11 +60,6 @@ export class PetService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * 
      * @summary Add a new pet to the store
@@ -282,7 +277,7 @@ export class PetService {
             throw new Error('Required parameter status was null or undefined when calling findPetsByStatus.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (status) {
             queryParameters.set('status', status.join(COLLECTION_FORMATS['csv']));
         }
@@ -321,7 +316,7 @@ export class PetService {
             throw new Error('Required parameter tags was null or undefined when calling findPetsByTags.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (tags) {
             queryParameters.set('tags', tags.join(COLLECTION_FORMATS['csv']));
         }
@@ -442,22 +437,34 @@ export class PetService {
         let consumes: string[] = [
             'application/x-www-form-urlencoded'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        let convertFormParamsToString = false;
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (name !== undefined) {
-            formParams.set('name', <any>name);
+            formParams.append('name', <any>name);
         }
         if (status !== undefined) {
-            formParams.set('status', <any>status);
+            formParams.append('status', <any>status);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
@@ -494,23 +501,37 @@ export class PetService {
         let consumes: string[] = [
             'multipart/form-data'
         ];
-        let canConsumeForm = this.canConsumeForm(consumes);
+        const canConsumeForm = this.canConsumeForm(consumes);
+
+        let formParams: { append(param: string, value: any): void; };
         let useForm = false;
+        let convertFormParamsToString = false;
+        // use FormData to transmit files using content-type "multipart/form-data"
+        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
         useForm = canConsumeForm;
-        let formParams = new (useForm ? FormData : URLSearchParams as any)() as {
-          set(param: string, value: any): void;
-        };
+        if (useForm) {
+            formParams = new FormData();
+        } else {
+            // TODO: this fails if a parameter is a file, the api can't consume "multipart/form-data" and a blob is passed.
+            convertFormParamsToString = true;
+            formParams = new URLSearchParams('', new CustomQueryEncoderHelper());
+            // set the content-type explicitly to avoid having it set to 'text/plain'
+            headers.set('Content-Type', 'application/x-www-form-urlencoded;charset=UTF-8');
+        }
+
+
+
         if (additionalMetadata !== undefined) {
-            formParams.set('additionalMetadata', <any>additionalMetadata);
+            formParams.append('additionalMetadata', <any>additionalMetadata);
         }
         if (file !== undefined) {
-            formParams.set('file', <any>file);
+            formParams.append('file', <any>file);
         }
 
         let requestOptions: RequestOptionsArgs = new RequestOptions({
             method: RequestMethod.Post,
             headers: headers,
-            body: formParams.toString(),
+            body: convertFormParamsToString ? formParams.toString() : formParams,
             withCredentials:this.configuration.withCredentials
         });
         // https://github.com/swagger-api/swagger-codegen/issues/4037
diff --git a/samples/client/petstore/typescript-angular-v4/npm/api/store.service.ts b/samples/client/petstore/typescript-angular-v4/npm/api/store.service.ts
index fba4c08d9aa..393d291ba3d 100644
--- a/samples/client/petstore/typescript-angular-v4/npm/api/store.service.ts
+++ b/samples/client/petstore/typescript-angular-v4/npm/api/store.service.ts
@@ -59,11 +59,6 @@ export class StoreService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
      * @summary Delete purchase order by ID
diff --git a/samples/client/petstore/typescript-angular-v4/npm/api/user.service.ts b/samples/client/petstore/typescript-angular-v4/npm/api/user.service.ts
index d7c9ee1510a..f495f1f9d39 100644
--- a/samples/client/petstore/typescript-angular-v4/npm/api/user.service.ts
+++ b/samples/client/petstore/typescript-angular-v4/npm/api/user.service.ts
@@ -59,11 +59,6 @@ export class UserService {
     }
 
 
-    public isJsonMime(mime: string): boolean {
-        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
-        return mime != null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
-    }
-
     /**
      * This can only be done by the logged in user.
      * @summary Create user
@@ -342,7 +337,7 @@ export class UserService {
             throw new Error('Required parameter password was null or undefined when calling loginUser.');
         }
 
-        let queryParameters = new URLSearchParams();
+        let queryParameters = new URLSearchParams('', new CustomQueryEncoderHelper());
         if (username !== undefined) {
             queryParameters.set('username', <any>username);
         }
diff --git a/samples/client/petstore/typescript-angular-v4/npm/encoder.ts b/samples/client/petstore/typescript-angular-v4/npm/encoder.ts
index 319f79da15a..6fcda7b246d 100644
--- a/samples/client/petstore/typescript-angular-v4/npm/encoder.ts
+++ b/samples/client/petstore/typescript-angular-v4/npm/encoder.ts
@@ -1,4 +1,4 @@
-import { QueryEncoder } from "@angular/http";
+    import { QueryEncoder } from '@angular/http';
 
 /**
 * CustomQueryEncoderHelper
@@ -14,4 +14,5 @@ export class CustomQueryEncoderHelper extends QueryEncoder {
         v = super.encodeValue(v);
         return v.replace(/\+/gi, '%2B');
     }
-}
\ No newline at end of file
+}
+