Assume rootDir is the current configuration directory

src/compiler/emitter.ts

@@ -646,7 +646,7 @@ export function getCommonSourceDirectory(
         commonSourceDirectory = getNormalizedAbsolutePath(options.rootDir, currentDirectory);
         checkSourceFilesBelongToPath?.(options.rootDir);
     }
-    else if (options.composite && options.configFilePath) {
+    else if (options.configFilePath) {
         // Project compilations never infer their root from the input source paths
         commonSourceDirectory = getDirectoryPath(normalizeSlashes(options.configFilePath));
         checkSourceFilesBelongToPath?.(commonSourceDirectory);

src/compiler/moduleNameResolver.ts

@@ -2884,7 +2884,7 @@ function getLoadModuleFromTargetExportOrImport(extensions: Extensions, state: Mo
                 const commonSourceDirGuesses: string[] = [];
                 // A `rootDir` compiler option strongly indicates the root location
                 // A `composite` project is using project references and has it's common src dir set to `.`, so it shouldn't need to check any other locations
-                if (state.compilerOptions.rootDir || (state.compilerOptions.composite && state.compilerOptions.configFilePath)) {
+                if (state.compilerOptions.rootDir || state.compilerOptions.configFilePath) {
                     const commonDir = toAbsolutePath(getCommonSourceDirectory(state.compilerOptions, () => [], state.host.getCurrentDirectory?.() || "", getCanonicalFileName));
                     commonSourceDirGuesses.push(commonDir);
                 }

src/compiler/utilities.ts

@@ -6622,7 +6622,7 @@ export function sourceFileMayBeEmitted(sourceFile: SourceFile, host: SourceFileM
     // Json file is not emitted if outDir is not specified
     if (!options.outDir) return false;
     // Otherwise if rootDir or composite config file, we know common sourceDir and can check if file would be emitted in same location
-    if (options.rootDir || (options.composite && options.configFilePath)) {
+    if (options.rootDir || options.configFilePath) {
         const commonDir = getNormalizedAbsolutePath(getCommonSourceDirectory(options, () => [], host.getCurrentDirectory(), host.getCanonicalFileName), host.getCurrentDirectory());
         const outputPath = getSourceFilePathInNewDirWorker(sourceFile.fileName, options.outDir, host.getCurrentDirectory(), commonDir, host.getCanonicalFileName);
         if (comparePaths(sourceFile.fileName, outputPath, host.getCurrentDirectory(), !host.useCaseSensitiveFileNames()) === Comparison.EqualTo) return false;

src/testRunner/unittests/helpers/monorepoSymlinkedSiblingPackages.ts

@@ -151,6 +151,7 @@ function getMonorepoSymlinkedSiblingPackagesSysWithUnRelatedFolders(
             compilerOptions: {
                 outDir: "lib",
                 declaration: true,
+                rootDir: "src",
             },
             include: ["src/**/*.ts"],
         }),
@@ -169,6 +170,7 @@ function getMonorepoSymlinkedSiblingPackagesSysWithUnRelatedFolders(
             compilerOptions: {
                 outDir: "lib",
                 declaration: true,
+                rootDir: "src",
             },
             include: ["src/**/*.ts"],
         }),
@@ -183,6 +185,7 @@ function getMonorepoSymlinkedSiblingPackagesSysWithUnRelatedFolders(
         "/home/src/projects/b/2/b-impl/b/tsconfig.json": jsonToReadableText({
             compilerOptions: {
                 outDir: "lib",
+                rootDir: "src",
             },
             include: ["src/**/*.ts"],
         }),

src/testRunner/unittests/tsbuild/outputPaths.ts

@@ -26,7 +26,7 @@ describe("unittests:: tsbuild:: outputPaths::", () => {
             ...input,
         });
 
-        it("verify getOutputFileNames", () => {
+        it("verify getOutputFileNames " + input.subScenario, () => {
             const sys = input.sys();
             assert.deepEqual(
                 ts.getOutputFileNames(
@@ -58,7 +58,7 @@ describe("unittests:: tsbuild:: outputPaths::", () => {
                 }),
             }),
         edits,
-    }, ["/home/src/workspaces/project/dist/index.js"]);
+    }, ["/home/src/workspaces/project/dist/src/index.js"]);
 
     verify({
         subScenario: "when rootDir is not specified and is composite",

tests/baselines/reference/commonSourceDirectory_dts.js

@@ -8,14 +8,14 @@ declare const y: number;
 export const x = y;
 
 
-//// [/app/bin/index.js]
+//// [/app/bin/src/index.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.x = void 0;
 /// <reference path="../lib/bar.d.ts" preserve="true" />
 exports.x = y;
-//# sourceMappingURL=../src/myMapRoot/index.js.map
+//# sourceMappingURL=../../myMapRoot/src/index.js.map
 
-//// [/app/bin/index.d.ts]
-/// <reference path="../lib/bar.d.ts" preserve="true" />
+//// [/app/bin/src/index.d.ts]
+/// <reference path="../../lib/bar.d.ts" preserve="true" />
 export declare const x: number;

tests/baselines/reference/commonSourceDirectory_dts.sourcemap.txt

@@ -1,12 +1,12 @@
 ===================================================================
 JsFile: index.js
-mapUrl: ../src/myMapRoot/index.js.map
+mapUrl: ../../myMapRoot/src/index.js.map
 sourceRoot: mySourceRoot/
-sources: index.ts
+sources: src/index.ts
 ===================================================================
 -------------------------------------------------------------------
-emittedFile:/app/bin/index.js
-sourceFile:index.ts
+emittedFile:/app/bin/src/index.js
+sourceFile:src/index.ts
 -------------------------------------------------------------------
 >>>"use strict";
 >>>Object.defineProperty(exports, "__esModule", { value: true });
@@ -26,7 +26,7 @@ sourceFile:index.ts
 4 >         ^^^
 5 >            ^
 6 >             ^
-7 >              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+7 >              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
   >export const 
 2 >
@@ -41,4 +41,4 @@ sourceFile:index.ts
 5 >Emitted(5, 14) Source(2, 19) + SourceIndex(0)
 6 >Emitted(5, 15) Source(2, 20) + SourceIndex(0)
 ---
->>>//# sourceMappingURL=../src/myMapRoot/index.js.map
+>>>//# sourceMappingURL=../../myMapRoot/src/index.js.map

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot_realRootFile.errors.txt

@@ -0,0 +1,32 @@
+error TS5055: Cannot write file '/bar.js' because it would overwrite input file.
+/root/a.ts(1,21): error TS6059: File '/foo.ts' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+/root/a.ts(2,21): error TS6059: File '/bar.js' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+
+
+!!! error TS5055: Cannot write file '/bar.js' because it would overwrite input file.
+==== /root/tsconfig.json (0 errors) ====
+    {
+        "compilerOptions": {
+            "baseUrl": ".",
+            "paths": {
+                "/*": ["./src/*"]
+            },
+            "allowJs": true,
+            "outDir": "bin"
+        }
+    }
+
+==== /root/a.ts (2 errors) ====
+    import { foo } from "/foo";
+                        ~~~~~~
+!!! error TS6059: File '/foo.ts' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+    import { bar } from "/bar";
+                        ~~~~~~
+!!! error TS6059: File '/bar.js' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+
+==== /foo.ts (0 errors) ====
+    export function foo() {}
+
+==== /bar.js (0 errors) ====
+    export function bar() {}
+

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot_realRootFile.js

@@ -16,11 +16,6 @@ import { bar } from "/bar";
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.foo = foo;
 function foo() { }
-//// [bar.js]
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.bar = bar;
-function bar() { }
 //// [a.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_noAliasWithRoot_realRootFile.errors.txt

@@ -0,0 +1,32 @@
+error TS5055: Cannot write file '/bar.js' because it would overwrite input file.
+/root/a.ts(1,21): error TS6059: File '/foo.ts' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+/root/a.ts(2,21): error TS6059: File '/bar.js' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+
+
+!!! error TS5055: Cannot write file '/bar.js' because it would overwrite input file.
+==== /root/tsconfig.json (0 errors) ====
+    {
+        "compilerOptions": {
+            "baseUrl": ".",
+            "paths": {
+                "*": ["./src/*"]
+            },
+            "allowJs": true,
+            "outDir": "bin"
+        }
+    }
+
+==== /root/a.ts (2 errors) ====
+    import { foo } from "/foo";
+                        ~~~~~~
+!!! error TS6059: File '/foo.ts' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+    import { bar } from "/bar";
+                        ~~~~~~
+!!! error TS6059: File '/bar.js' is not under 'rootDir' '/root'. 'rootDir' is expected to contain all source files.
+
+==== /foo.ts (0 errors) ====
+    export function foo() {}
+
+==== /bar.js (0 errors) ====
+    export function bar() {}
+

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_noAliasWithRoot_realRootFile.js

@@ -16,11 +16,6 @@ import { bar } from "/bar";
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.foo = foo;
 function foo() { }
-//// [bar.js]
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.bar = bar;
-function bar() { }
 //// [a.js]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/tsbuild/declarationEmit/outFile/reports-dts-generation-errors-with-incremental.js

@@ -72,7 +72,7 @@ Found 1 error.
 
 
 //// [/home/src/workspaces/project/outFile.js]
-define("index", ["require", "exports", "ky"], function (require, exports, ky_1) {
+define("src/index", ["require", "exports", "ky"], function (require, exports, ky_1) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     exports.api = void 0;

tests/baselines/reference/tsbuild/declarationEmit/outFile/reports-dts-generation-errors.js

@@ -73,7 +73,7 @@ Found 1 error.
 
 
 //// [/home/src/workspaces/project/outFile.js]
-define("index", ["require", "exports", "ky"], function (require, exports, ky_1) {
+define("src/index", ["require", "exports", "ky"], function (require, exports, ky_1) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     exports.api = void 0;