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Give more specific errors for verbatimModuleSyntax #62113

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Merged
merged 4 commits into from
Jul 23, 2025
Merged

Give more specific errors for verbatimModuleSyntax #62113

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2fac055
Update error message.
DanielRosenwasser Jul 23, 2025
35a988d
Accept baselines.
DanielRosenwasser Jul 23, 2025
78dee4e
Merge remote-tracking branch 'origin' into esmMessageVerbatimModuleSy…
DanielRosenwasser Jul 23, 2025
8c15919
Format.
DanielRosenwasser Jul 23, 2025
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21 changes: 17 additions & 4 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -2510,6 +2510,19 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
return diagnostic;
}

function getVerbatimModuleSyntaxErrorMessage(node: Node): DiagnosticMessage {
const sourceFile = getSourceFileOfNode(node);
const fileName = sourceFile.fileName;

// Check if the file is .cts or .cjs (CommonJS-specific extensions)
if (fileExtensionIsOneOf(fileName, [Extension.Cts, Extension.Cjs])) {
return Diagnostics.ECMAScript_imports_and_exports_cannot_be_written_in_a_CommonJS_file_under_verbatimModuleSyntax;
} else {
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Copilot AI Jul 23, 2025

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The error message for .cts/.cjs files should provide guidance on how to resolve the issue, similar to the detailed message used for other file types. Currently it only states what's wrong without offering solutions.

Suggested change
} else {
if (fileExtensionIsOneOf(fileName, [Extension.Cts, Extension.Cjs])) {
return Diagnostics.ECMAScript_imports_and_exports_cannot_be_written_in_a_CommonJS_file_under_verbatimModuleSyntax_Adjust_the_type_field_in_the_nearest_package_json_to_make_this_file_an_ECMAScript_module_or_adjust_your_verbatimModuleSyntax_module_and_moduleResolution_settings_in_TypeScript;
} else {

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// For .ts, .tsx, .js, etc.
return Diagnostics.ECMAScript_imports_and_exports_cannot_be_written_in_a_CommonJS_file_under_verbatimModuleSyntax_Adjust_the_type_field_in_the_nearest_package_json_to_make_this_file_an_ECMAScript_module_or_adjust_your_verbatimModuleSyntax_module_and_moduleResolution_settings_in_TypeScript;
}
}

function addErrorOrSuggestion(isError: boolean, diagnostic: Diagnostic) {
if (isError) {
diagnostics.add(diagnostic);
Expand Down Expand Up @@ -47966,7 +47979,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
!isInJSFile(node) &&
host.getEmitModuleFormatOfFile(getSourceFileOfNode(node)) === ModuleKind.CommonJS
) {
error(node, Diagnostics.ESM_syntax_is_not_allowed_in_a_CommonJS_module_when_verbatimModuleSyntax_is_enabled);
error(node, getVerbatimModuleSyntaxErrorMessage(node));
}
else if (
moduleKind === ModuleKind.Preserve &&
Expand All @@ -47978,7 +47991,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
// when we look at the `impliedNodeFormat` of this file and decide it's CommonJS (i.e., currently,
// only if the file extension is .cjs/.cts). To avoid that inconsistency, we disallow ESM syntax
// in files that are unambiguously CommonJS in this mode.
error(node, Diagnostics.ESM_syntax_is_not_allowed_in_a_CommonJS_module_when_module_is_set_to_preserve);
error(node, Diagnostics.ECMAScript_module_syntax_is_not_allowed_in_a_CommonJS_module_when_module_is_set_to_preserve);
}

if (
Expand Down Expand Up @@ -48394,7 +48407,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
}

if (isIllegalExportDefaultInCJS) {
error(node, Diagnostics.ESM_syntax_is_not_allowed_in_a_CommonJS_module_when_verbatimModuleSyntax_is_enabled);
error(node, getVerbatimModuleSyntaxErrorMessage(node));
}

checkExternalModuleExports(container);
Expand Down Expand Up @@ -52878,7 +52891,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {

function checkGrammarImportCallExpression(node: ImportCall): boolean {
if (compilerOptions.verbatimModuleSyntax && moduleKind === ModuleKind.CommonJS) {
return grammarErrorOnNode(node, Diagnostics.ESM_syntax_is_not_allowed_in_a_CommonJS_module_when_verbatimModuleSyntax_is_enabled);
return grammarErrorOnNode(node, getVerbatimModuleSyntaxErrorMessage(node));
}

if (moduleKind === ModuleKind.ES2015) {
Expand Down
8 changes: 6 additions & 2 deletions src/compiler/diagnosticMessages.json
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Original file line number Diff line number Diff line change
Expand Up @@ -939,7 +939,7 @@
"category": "Error",
"code": 1285
},
"ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.": {
"ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'.": {
"category": "Error",
"code": 1286
},
Expand Down Expand Up @@ -967,10 +967,14 @@
"category": "Error",
"code": 1292
},
"ESM syntax is not allowed in a CommonJS module when 'module' is set to 'preserve'.": {
"ECMAScript module syntax is not allowed in a CommonJS module when 'module' is set to 'preserve'.": {
"category": "Error",
"code": 1293
},
"ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.": {
"category": "Error",
"code": 1295
},

"'with' statements are not allowed in an async function block.": {
"category": "Error",
Expand Down
12 changes: 6 additions & 6 deletions ...dulesShadowGlobalTypeNotValue(isolatedmodules=false,verbatimmodulesyntax=true).errors.txt
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
bad.ts(1,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,10): error TS1484: 'Date' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
bad.ts(1,16): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,16): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,16): error TS1484: 'Event' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
good.ts(2,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.


==== ./types.ts (0 errors) ====
Expand Down Expand Up @@ -36,11 +36,11 @@ good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when
==== ./bad.ts (4 errors) ====
import { Date, Event } from './types';
~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~~~
!!! error TS1484: 'Date' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
~~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~~~~
!!! error TS1484: 'Event' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
function foo(a: Date) {
Expand All @@ -55,7 +55,7 @@ good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when
import type { Date, Event } from './types';
import { Console } from 'node:console';
~~~~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
function foo(a: Date) {
const b = new Date(a.year, a.month, a.day);
return b.getTime();
Expand Down
12 changes: 6 additions & 6 deletions ...odulesShadowGlobalTypeNotValue(isolatedmodules=true,verbatimmodulesyntax=true).errors.txt
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Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@
bad.ts(1,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,10): error TS1484: 'Date' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS2866: Import 'Date' conflicts with global value used in this file, so must be declared with a type-only import when 'isolatedModules' is enabled.
bad.ts(1,16): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,16): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,16): error TS1484: 'Event' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
bad.ts(1,16): error TS2866: Import 'Event' conflicts with global value used in this file, so must be declared with a type-only import when 'isolatedModules' is enabled.
good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
good.ts(2,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.


==== ./types.ts (0 errors) ====
Expand Down Expand Up @@ -38,13 +38,13 @@ good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when
==== ./bad.ts (6 errors) ====
import { Date, Event } from './types';
~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~~~
!!! error TS1484: 'Date' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
~~~~
!!! error TS2866: Import 'Date' conflicts with global value used in this file, so must be declared with a type-only import when 'isolatedModules' is enabled.
~~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~~~~
!!! error TS1484: 'Event' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
~~~~~
Expand All @@ -61,7 +61,7 @@ good.ts(2,10): error TS1286: ESM syntax is not allowed in a CommonJS module when
import type { Date, Event } from './types';
import { Console } from 'node:console';
~~~~~~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
function foo(a: Date) {
const b = new Date(a.year, a.month, a.day);
return b.getTime();
Expand Down
4 changes: 2 additions & 2 deletions ...ModulesSketchyAliasLocalMerge(isolatedmodules=false,verbatimmodulesyntax=true).errors.txt
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
bad.ts(1,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,10): error TS1484: 'FC' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.


Expand All @@ -8,7 +8,7 @@ bad.ts(1,10): error TS1484: 'FC' is a type and must be imported using a type-onl
==== bad.ts (2 errors) ====
import { FC } from "./types";
~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~
!!! error TS1484: 'FC' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
let FC: FC | null = null;
Expand Down
4 changes: 2 additions & 2 deletions ...dModulesSketchyAliasLocalMerge(isolatedmodules=true,verbatimmodulesyntax=true).errors.txt
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
bad.ts(1,10): error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
bad.ts(1,10): error TS1484: 'FC' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
bad.ts(1,10): error TS2865: Import 'FC' conflicts with local value, so must be declared with a type-only import when 'isolatedModules' is enabled.

Expand All @@ -9,7 +9,7 @@ bad.ts(1,10): error TS2865: Import 'FC' conflicts with local value, so must be d
==== bad.ts (3 errors) ====
import { FC } from "./types";
~~
!!! error TS1286: ESM syntax is not allowed in a CommonJS module when 'verbatimModuleSyntax' is enabled.
!!! error TS1295: ECMAScript imports and exports cannot be written in a CommonJS file under 'verbatimModuleSyntax'. Adjust the 'type' field in the nearest 'package.json' to make this file an ECMAScript module, or adjust your 'verbatimModuleSyntax', 'module', and 'moduleResolution' settings in TypeScript.
~~
!!! error TS1484: 'FC' is a type and must be imported using a type-only import when 'verbatimModuleSyntax' is enabled.
~~
Expand Down
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