Add F# Functions server generator (#3933)

* cherry pick F# Functions generator

test fix

fix template paths

replace giraffe sample

* update doc

Author: nmfisher

bin/fsharp-functions-server-petstore.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+
+SCRIPT="$0"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=$(ls -ld "$SCRIPT")
+  link=$(expr "$ls" : '.*-> \(.*\)$')
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=$(dirname "$SCRIPT")/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=$(dirname "$SCRIPT")/..
+  APP_DIR=$(cd "${APP_DIR}"; pwd)
+fi
+
+executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
+ags="$@ generate -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g fsharp-functions -o samples/server/petstore/fsharp-functions"
+
+java ${JAVA_OPTS} -jar ${executable} ${ags}

bin/windows/fsharp-functions-server-petstore.bat

@@ -0,0 +1,10 @@
+set executable=.\modules\openapi-generator-cli\target\openapi-generator-cli.jar
+
+If Not Exist %executable% (
+  mvn clean package
+)
+
+REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M -DloggerPath=conf/log4j.properties
+set ags=generate  --artifact-id "fsharp-functions-petstore-server" -i modules\openapi-generator\src\test\resources\2_0\petstore.yaml -g fsharp-functions -o samples\server\petstore\fsharp-functions
+
+java %JAVA_OPTS% -jar %executable% %ags%

docs/generators.md

@@ -75,6 +75,7 @@ The following generators are available:
 * [cpp-restbed-server](generators/cpp-restbed-server)  
 * [csharp-nancyfx](generators/csharp-nancyfx)  
 * [erlang-server](generators/erlang-server)  
+* [fsharp-functions](generators/fsharp-functions)  
 * [fsharp-giraffe-server](generators/fsharp-giraffe-server)  
 * [go-gin-server](generators/go-gin-server)  
 * [go-server](generators/go-server)  

docs/generators/fsharp-functions.md

@@ -0,0 +1,22 @@
+
+---
+id: generator-opts-server-fsharp-functions
+title: Config Options for fsharp-functions
+sidebar_label: fsharp-functions
+---
+
+| Option | Description | Values | Default |
+| ------ | ----------- | ------ | ------- |
+|sortParamsByRequiredFlag|Sort method arguments to place required parameters before optional parameters.| |true|
+|ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
+|allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
+|licenseUrl|The URL of the license| |http://localhost|
+|licenseName|The name of the license| |NoLicense|
+|packageCopyright|Specifies an AssemblyCopyright for the .NET Framework global assembly attributes stored in the AssemblyInfo file.| |No Copyright|
+|packageAuthors|Specifies Authors property in the .NET Core project file.| |OpenAPI|
+|packageTitle|Specifies an AssemblyTitle for the .NET Framework global assembly attributes stored in the AssemblyInfo file.| |OpenAPI Library|
+|packageName|F# module name (convention: Title.Case).| |OpenAPI|
+|packageVersion|F# package version.| |1.0.0|
+|packageGuid|The GUID that will be associated with the C# project| |null|
+|sourceFolder|source folder for generated code| |OpenAPI/src|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java

@@ -29,11 +29,13 @@
 import org.openapitools.codegen.utils.ModelUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import java.lang.Exception;
 
 import java.io.File;
 import java.util.*;
 
 import static org.openapitools.codegen.utils.StringUtils.camelize;
+import static org.openapitools.codegen.utils.StringUtils.underscore;
 
 public abstract class AbstractFSharpCodegen extends DefaultCodegen implements CodegenConfig {
 
@@ -246,11 +248,6 @@ public void processOpts() {
             additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
         }
 
-        if (additionalProperties.containsKey(CodegenConstants.INVOKER_PACKAGE)) {
-            LOGGER.warn(String.format(Locale.ROOT, "%s is not used by F# generators. Please use %s",
-                    CodegenConstants.INVOKER_PACKAGE, CodegenConstants.PACKAGE_NAME));
-        }
-
         // {{packageTitle}}
         if (additionalProperties.containsKey(CodegenConstants.PACKAGE_TITLE)) {
             setPackageTitle((String) additionalProperties.get(CodegenConstants.PACKAGE_TITLE));
@@ -300,32 +297,8 @@ public void processOpts() {
             additionalProperties.put(CodegenConstants.USE_DATETIME_OFFSET, useDateTimeOffsetFlag);
         }
 
-        if (additionalProperties.containsKey(CodegenConstants.USE_COLLECTION)) {
-            setUseCollection(convertPropertyToBooleanAndWriteBack(CodegenConstants.USE_COLLECTION));
-        } else {
-            additionalProperties.put(CodegenConstants.USE_COLLECTION, useCollection);
-        }
-
-        if (additionalProperties.containsKey(CodegenConstants.RETURN_ICOLLECTION)) {
-            setReturnICollection(convertPropertyToBooleanAndWriteBack(CodegenConstants.RETURN_ICOLLECTION));
-        } else {
-            additionalProperties.put(CodegenConstants.RETURN_ICOLLECTION, returnICollection);
-        }
-
-        if (additionalProperties.containsKey(CodegenConstants.NETCORE_PROJECT_FILE)) {
-            setNetCoreProjectFileFlag(convertPropertyToBooleanAndWriteBack(CodegenConstants.NETCORE_PROJECT_FILE));
-        } else {
-            additionalProperties.put(CodegenConstants.NETCORE_PROJECT_FILE, netCoreProjectFileFlag);
-        }
-
-        if (additionalProperties.containsKey(CodegenConstants.INTERFACE_PREFIX)) {
-            String useInterfacePrefix = additionalProperties.get(CodegenConstants.INTERFACE_PREFIX).toString();
-            if ("false".equals(useInterfacePrefix.toLowerCase(Locale.ROOT))) {
-                setInterfacePrefix("");
-            } else if (!"true".equals(useInterfacePrefix.toLowerCase(Locale.ROOT))) {
-                // NOTE: if user passes "true" explicitly, we use the default I- prefix. The other supported case here is a custom prefix.
-                setInterfacePrefix(sanitizeName(useInterfacePrefix));
-            }
+        if (additionalProperties.containsKey(CodegenConstants.MODEL_PROPERTY_NAMING)) {
+          setModelPropertyNaming((String) additionalProperties.get(CodegenConstants.MODEL_PROPERTY_NAMING));
         }
 
         // This either updates additionalProperties with the above fixes, or sets the default if the option was not specified.
@@ -372,65 +345,49 @@ public Map<String, Object> postProcessAllModels(Map<String, Object> objs) {
     }
 
     /*
-     * F# does not allow forward declarations, so files must be imported in the correct order.
-     * Output of CodeGen models must therefore bein dependency order (rather than alphabetical order, which seems to be the default).
-     * We achieve this by creating a comparator to check whether the first model contains any properties of the comparison model's type
-     * This could probably be made more efficient if absolutely needed.
-     */
+    * F# does not allow forward declarations, so files must be imported in the correct order.
+    * Output of CodeGen models must therefore bein dependency order (rather than alphabetical order, which seems to be the default).    
+    * This could probably be made more efficient if absolutely needed.
+    */
     @SuppressWarnings({"unchecked"})
-    public Map<String, Object> postProcessDependencyOrders(final Map<String, Object> objs) {
-        Comparator<String> comparator = new Comparator<String>() {
-            @Override
-            public int compare(String key1, String key2) {
-                // Get the corresponding models
-                CodegenModel model1 = ModelUtils.getModelByName(key1, objs);
-                CodegenModel model2 = ModelUtils.getModelByName(key2, objs);
-
-                List<String> complexVars1 = new ArrayList<String>();
-                List<String> complexVars2 = new ArrayList<String>();
-
-                for (CodegenProperty prop : model1.vars) {
-                    if (prop.complexType != null)
-                        complexVars1.add(prop.complexType);
-                }
-                for (CodegenProperty prop : model2.vars) {
-                    if (prop.complexType != null)
-                        complexVars2.add(prop.complexType);
-                }
-
-                // if first has complex vars and second has none, first is greater
-                if (complexVars1.size() > 0 && complexVars2.size() == 0)
-                    return 1;
-
-                // if second has complex vars and first has none, first is lesser
-                if (complexVars1.size() == 0 && complexVars2.size() > 0)
-                    return -1;
-
-                // if first has complex var that matches the second's key, first is greater
-                if (complexVars1.contains(key2))
-                    return 1;
-
-                // if second has complex var that matches the first's key, first is lesser
-                if (complexVars2.contains(key1))
-                    return -1;
-
-                // if none of the above, don't care
-                return 0;
-
-            }
-        };
-        PriorityQueue<String> queue = new PriorityQueue<String>(objs.size(), comparator);
-        for (Object k : objs.keySet()) {
-            queue.add(k.toString());
+    public Map<String,Object> postProcessDependencyOrders(final Map<String, Object> objs) {
+        
+      Map<String,Set<String>> dependencies = new HashMap<String,Set<String>>();
+
+      List<String> classNames = new ArrayList<String>();
+        
+      for(String k : objs.keySet()) {
+        CodegenModel model = ModelUtils.getModelByName(k, objs);
+        if(model == null || model.classname == null) {
+          throw new RuntimeException("Null model encountered");
         }
-
-        Map<String, Object> sorted = new LinkedHashMap<String, Object>();
-
-        while (queue.size() > 0) {
-            String key = queue.poll();
-            sorted.put(key, objs.get(key));
+        dependencies.put(model.classname, model.imports);
+        
+        classNames.add(model.classname);
+      }
+      
+      Object[] sortedKeys = classNames.toArray();
+
+      for(int i1 = 0 ; i1 < sortedKeys.length; i1++) {
+        String k1 = sortedKeys[i1].toString();
+        for(int i2 = i1 + 1; i2 < sortedKeys.length; i2++) {
+          String k2 = sortedKeys[i2].toString();
+          if(dependencies.get(k2).contains(k1)) {
+            sortedKeys[i2] = k1;
+            sortedKeys[i1] = k2;
+            i1 = -1;
+            break;
+          }
         }
-        return sorted;
+      }
+      
+      Map<String,Object> sorted = new LinkedHashMap<String,Object>();
+      for(int i = sortedKeys.length - 1; i >= 0;  i--) {
+        Object k = sortedKeys[i];
+        sorted.put(k.toString(), objs.get(k));
+      }
+
+      return sorted;
     }
 
     /**
@@ -684,6 +641,39 @@ public String toOperationId(String operationId) {
         return camelize(sanitizeName(operationId));
     }
 
+    public String getModelPropertyNaming() {
+        return this.modelPropertyNaming;
+    }
+
+    public void setModelPropertyNaming(String naming) {
+        if ("original".equals(naming) || "camelCase".equals(naming) ||
+                "PascalCase".equals(naming) || "snake_case".equals(naming)) {
+            this.modelPropertyNaming = naming;
+        } else {
+            throw new IllegalArgumentException("Invalid model property naming '" +
+                    naming + "'. Must be 'original', 'camelCase', " +
+                    "'PascalCase' or 'snake_case'");
+        }
+    }
+
+    
+    public String getNameUsingModelPropertyNaming(String name) {
+      switch (CodegenConstants.MODEL_PROPERTY_NAMING_TYPE.valueOf(getModelPropertyNaming())) {
+          case original:
+              return name;
+          case camelCase:
+              return camelize(name, true);
+          case PascalCase:
+              return camelize(name);
+          case snake_case:
+              return underscore(name);
+          default:
+              throw new IllegalArgumentException("Invalid model property naming '" +
+                      name + "'. Must be 'original', 'camelCase', " +
+                      "'PascalCase' or 'snake_case'");
+      }
+  }
+
     @Override
     public String toVarName(String name) {
         // sanitize name
@@ -694,9 +684,8 @@ public String toVarName(String name) {
             return name;
         }
 
-        // camelize the variable name
-        // pet_id => PetId
-        name = camelize(name);
+        name = getNameUsingModelPropertyNaming(name);
+
         // for reserved word or word starting with number, append _
         if (isReservedWord(name) || name.matches("^\\d.*")) {
             name = escapeReservedWord(name);