Add new option "libReplacement"

src/compiler/commandLineParser.ts

@@ -865,6 +865,14 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         affectsBuildInfo: true,
         affectsSemanticDiagnostics: true,
     },
+    {
+        name: "libReplacement",
+        type: "boolean",
+        affectsProgramStructure: true,
+        category: Diagnostics.Language_and_Environment,
+        description: Diagnostics.Enable_lib_replacement,
+        defaultValueDescription: true,
+    },
 
     // Strict Type Checks
     {

src/compiler/diagnosticMessages.json

@@ -6502,6 +6502,10 @@
         "category": "Error",
         "code": 6807
     },
+    "Enable lib replacement.": {
+        "category": "Message",
+        "code": 6808
+    },
 
     "one of:": {
         "category": "Message",

src/compiler/program.ts

@@ -3937,6 +3937,17 @@ export function createProgram(_rootNamesOrOptions: readonly string[] | CreatePro
         const existing = resolvedLibProcessing?.get(libFileName);
         if (existing) return existing;
 
+        if (options.libReplacement === false) {
+            const result: LibResolution = {
+                resolution: {
+                    resolvedModule: undefined,
+                },
+                actual: combinePaths(defaultLibraryPath, libFileName),
+            };
+            (resolvedLibProcessing ??= new Map()).set(libFileName, result);
+            return result;
+        }
+
         if (structureIsReused !== StructureIsReused.Not && oldProgram && !hasInvalidatedLibResolutions(libFileName)) {
             const oldResolution = oldProgram.resolvedLibReferences?.get(libFileName);
             if (oldResolution) {

src/compiler/types.ts

@@ -7411,6 +7411,7 @@ export interface CompilerOptions {
     /** @deprecated */
     keyofStringsOnly?: boolean;
     lib?: string[];
+    libReplacement?: boolean;
     /** @internal */ listEmittedFiles?: boolean;
     /** @internal */ listFiles?: boolean;
     /** @internal */ explainFiles?: boolean;

src/testRunner/unittests/helpers/libraryResolution.ts

@@ -21,23 +21,23 @@ function getSysForLibResolution(libRedirection?: boolean, forTsserver?: boolean)
             /// <reference lib="es5"/>
         `,
         "/home/src/workspace/projects/project1/tsconfig.json": jsonToReadableText({
-            compilerOptions: { composite: true, typeRoots: ["./typeroot1"], lib: ["es5", "dom"], traceResolution: true },
+            compilerOptions: { composite: true, typeRoots: ["./typeroot1"], lib: ["es5", "dom"], traceResolution: true, libReplacement: libRedirection },
         }),
         "/home/src/workspace/projects/project1/typeroot1/sometype/index.d.ts": `export type TheNum = "type1";`,
         "/home/src/workspace/projects/project2/utils.d.ts": `export const y = 10;`,
         "/home/src/workspace/projects/project2/index.ts": `export const y = 10`,
         "/home/src/workspace/projects/project2/tsconfig.json": jsonToReadableText({
-            compilerOptions: { composite: true, lib: ["es5", "dom"], traceResolution: true },
+            compilerOptions: { composite: true, lib: ["es5", "dom"], traceResolution: true, libReplacement: libRedirection },
         }),
         "/home/src/workspace/projects/project3/utils.d.ts": `export const y = 10;`,
         "/home/src/workspace/projects/project3/index.ts": `export const z = 10`,
         "/home/src/workspace/projects/project3/tsconfig.json": jsonToReadableText({
-            compilerOptions: { composite: true, lib: ["es5", "dom"], traceResolution: true },
+            compilerOptions: { composite: true, lib: ["es5", "dom"], traceResolution: true, libReplacement: libRedirection },
         }),
         "/home/src/workspace/projects/project4/utils.d.ts": `export const y = 10;`,
         "/home/src/workspace/projects/project4/index.ts": `export const z = 10`,
         "/home/src/workspace/projects/project4/tsconfig.json": jsonToReadableText({
-            compilerOptions: { composite: true, lib: ["esnext", "dom", "webworker"], traceResolution: true },
+            compilerOptions: { composite: true, lib: ["esnext", "dom", "webworker"], traceResolution: true, libReplacement: libRedirection },
         }),
         [getTypeScriptLibTestLocation("dom")]: "interface DOMInterface { }",
         [getTypeScriptLibTestLocation("webworker")]: "interface WebWorkerInterface { }",
@@ -71,6 +71,7 @@ function getLibResolutionEditOptions(
                                 typeRoots: ["./typeroot1", "./typeroot2"],
                                 lib: ["es5", "dom"],
                                 traceResolution: true,
+                                libReplacement: true,
                             },
                         }),
                     ),
@@ -90,6 +91,7 @@ function getLibResolutionEditOptions(
                                 typeRoots: ["./typeroot1"],
                                 lib: ["es5", "dom"],
                                 traceResolution: true,
+                                libReplacement: true,
                             },
                         }),
                     );
@@ -235,6 +237,7 @@ export function getSysForLibResolutionUnknown(): TestServerHost {
             compilerOptions: {
                 composite: true,
                 traceResolution: true,
+                libReplacement: true,
             },
         }),
         [getTypeScriptLibTestLocation("webworker")]: "interface WebWorkerInterface { }",

tests/baselines/reference/api/typescript.d.ts

@@ -7027,6 +7027,7 @@ declare namespace ts {
         /** @deprecated */
         keyofStringsOnly?: boolean;
         lib?: string[];
+        libReplacement?: boolean;
         locale?: string;
         mapRoot?: string;
         maxNodeModuleJsDepth?: number;

tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es5",                                     /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     "jsx": "react",                                      /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     "lib": ["es5","es2015.promise"],                     /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     "lib": ["es5","es2015.core"],                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json

@@ -14,6 +14,7 @@
     "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "libReplacement": true,                           /* Enable lib replacement. */
     // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
     // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/libReplacement/tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "libReplacement": true
+    }
+}

tests/baselines/reference/libReplacement(libreplacement=false).trace.json

@@ -0,0 +1 @@
+[]