path mappings now supports rooted disk paths and urls - fixes #13730

Author: EECOLOR

src/compiler/moduleNameResolver.ts

@@ -730,6 +730,9 @@ namespace ts {
     function tryLoadModuleUsingOptionalResolutionSettings(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
         state: ModuleResolutionState): Resolved | undefined {
 
+        const resolved = tryLoadModuleUsingPathsIfEligible(extensions, moduleName, loader, state);
+        if (resolved) return resolved.value;
+
         if (!isExternalModuleNameRelative(moduleName)) {
             return tryLoadModuleUsingBaseUrl(extensions, moduleName, loader, state);
         }
@@ -738,6 +741,24 @@ namespace ts {
         }
     }
 
+    function tryLoadModuleUsingPathsIfEligible(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, state: ModuleResolutionState) {
+        const { baseUrl, paths } = state.compilerOptions;
+        if (baseUrl && paths && isEligibleForPathMapping(moduleName, paths)) {
+            if (state.traceEnabled) trace(state.host, Diagnostics.paths_option_is_specified_looking_for_a_pattern_to_match_module_name_0, moduleName);
+            return tryLoadModuleUsingPaths(extensions, moduleName, baseUrl, paths, loader, /*onlyRecordFailures*/ false, state);
+        }
+    }
+
+    function isEligibleForPathMapping(moduleName: string, paths: MapLike<string[]>): boolean {
+        if (isRootedDiskPath(moduleName) || isUrl(moduleName)) {
+            // check for potential alias otherwise { '*': './src/*' } will match
+            const root = moduleName.slice(0, getRootLength(moduleName));
+            const potentialAlias = find(getOwnKeys(paths), path => startsWith(path, root));
+            return !!potentialAlias;
+        }
+        else return !pathIsRelative(moduleName);
+    }
+
     function tryLoadModuleUsingRootDirs(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
         state: ModuleResolutionState): Resolved | undefined {
 
@@ -816,22 +837,13 @@ namespace ts {
     }
 
     function tryLoadModuleUsingBaseUrl(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, state: ModuleResolutionState): Resolved | undefined {
-        const { baseUrl, paths } = state.compilerOptions;
+        const { baseUrl } = state.compilerOptions;
         if (!baseUrl) {
             return undefined;
         }
         if (state.traceEnabled) {
             trace(state.host, Diagnostics.baseUrl_option_is_set_to_0_using_this_value_to_resolve_non_relative_module_name_1, baseUrl, moduleName);
         }
-        if (paths) {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.paths_option_is_specified_looking_for_a_pattern_to_match_module_name_0, moduleName);
-            }
-            const resolved = tryLoadModuleUsingPaths(extensions, moduleName, baseUrl, paths, loader, /*onlyRecordFailures*/ false, state);
-            if (resolved) {
-                return resolved.value;
-            }
-        }
         const candidate = normalizePath(combinePaths(baseUrl, moduleName));
         if (state.traceEnabled) {
             trace(state.host, Diagnostics.Resolving_module_name_0_relative_to_base_url_1_2, moduleName, baseUrl, candidate);

src/services/stringCompletions.ts

@@ -247,16 +247,17 @@ namespace ts.Completions.StringCompletions {
         const scriptPath = sourceFile.path;
         const scriptDirectory = getDirectoryPath(scriptPath);
 
-        const extensionOptions = getExtensionOptions(compilerOptions);
-        if (isPathRelativeToScript(literalValue) || isRootedDiskPath(literalValue)) {
-            if (compilerOptions.rootDirs) {
-                return getCompletionEntriesForDirectoryFragmentWithRootDirs(
-                    compilerOptions.rootDirs, literalValue, scriptDirectory, extensionOptions, compilerOptions, host, scriptPath);
+        if (isRootedDiskPath(literalValue) || isUrl(literalValue)) {
+            if (compilerOptions.baseUrl) {
+                return getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, compilerOptions, host, typeChecker);
             }
             else {
-                return getCompletionEntriesForDirectoryFragment(literalValue, scriptDirectory, extensionOptions, host, scriptPath);
+                return getCompletionEntriesForRelativeModules(literalValue, scriptDirectory, compilerOptions, host, scriptPath);
             }
         }
+        else if (isPathRelativeToScript(literalValue)) {
+            return getCompletionEntriesForRelativeModules(literalValue, scriptDirectory, compilerOptions, host, scriptPath);
+        }
         else {
             return getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, compilerOptions, host, typeChecker);
         }
@@ -269,6 +270,17 @@ namespace ts.Completions.StringCompletions {
     function getExtensionOptions(compilerOptions: CompilerOptions, includeExtensions = false): ExtensionOptions {
         return { extensions: getSupportedExtensionsForModuleResolution(compilerOptions), includeExtensions };
     }
+    function getCompletionEntriesForRelativeModules(literalValue: string, scriptDirectory: string, compilerOptions: CompilerOptions, host: LanguageServiceHost, scriptPath: Path) {
+        const extensionOptions = getExtensionOptions(compilerOptions);
+        if (compilerOptions.rootDirs) {
+            return getCompletionEntriesForDirectoryFragmentWithRootDirs(
+                compilerOptions.rootDirs, literalValue, scriptDirectory, extensionOptions, compilerOptions, host, scriptPath);
+        }
+        else {
+            return getCompletionEntriesForDirectoryFragment(literalValue, scriptDirectory, extensionOptions, host, scriptPath);
+        }
+    }
+
     function getSupportedExtensionsForModuleResolution(compilerOptions: CompilerOptions): ReadonlyArray<Extension> {
         const extensions = getSupportedExtensions(compilerOptions);
         return compilerOptions.resolveJsonModule && getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeJs ?

src/testRunner/unittests/moduleResolution.ts

@@ -757,6 +757,9 @@ import b = require("./moduleB");
                         ],
                         "somefolder/*": [
                             "someanotherfolder/*"
+                        ],
+                        "/rooted/*": [
+                            "generated/*"
                         ]
                     }
                 };
@@ -773,6 +776,7 @@ import b = require("./moduleB");
                     "/root/folder1/file2/index.d.ts",
                     // then first attempt on 'generated/*' was successful
                 ]);
+                check("/rooted/folder1/file2", file2, []);
                 check("folder2/file3", file3, [
                     // first try '*'
                     "/root/folder2/file3.ts",
@@ -900,6 +904,9 @@ import b = require("./moduleB");
                         ],
                         "somefolder/*": [
                             "someanotherfolder/*"
+                        ],
+                        "/rooted/*": [
+                            "generated/*"
                         ]
                     }
                 };
@@ -911,6 +918,7 @@ import b = require("./moduleB");
                     "/root/folder1/file2.d.ts",
                     // success when using 'generated/*'
                 ]);
+                check("/rooted/folder1/file2", file2, []);
                 check("folder1/file3", file3, [
                     // first try '*'
                     "/root/folder1/file3.ts",

tests/baselines/reference/pathMappingBasedModuleResolution5_classic.trace.json

@@ -1,15 +1,13 @@
 [
     "======== Resolving module 'folder2/file1' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'folder2/file1'.",
     "'paths' option is specified, looking for a pattern to match module name 'folder2/file1'.",
     "Module name 'folder2/file1', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'folder2/file1'.",
     "File 'c:/root/folder2/file1.ts' exist - use it as a name resolution result.",
     "======== Module name 'folder2/file1' was successfully resolved to 'c:/root/folder2/file1.ts'. ========",
     "======== Resolving module 'folder3/file2' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'folder3/file2'.",
     "'paths' option is specified, looking for a pattern to match module name 'folder3/file2'.",
     "Module name 'folder3/file2', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'folder3/file2'.",
@@ -18,15 +16,13 @@
     "======== Module name 'folder3/file2' was successfully resolved to 'c:/root/generated/folder3/file2.ts'. ========",
     "======== Resolving module 'components/file3' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'components/file3'.",
     "'paths' option is specified, looking for a pattern to match module name 'components/file3'.",
     "Module name 'components/file3', matched pattern 'components/*'.",
     "Trying substitution 'shared/components/*', candidate module location: 'shared/components/file3'.",
     "File 'c:/root/shared/components/file3.ts' exist - use it as a name resolution result.",
     "======== Module name 'components/file3' was successfully resolved to 'c:/root/shared/components/file3.ts'. ========",
     "======== Resolving module 'file4' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'file4'.",
     "'paths' option is specified, looking for a pattern to match module name 'file4'.",
     "Module name 'file4', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'file4'.",

tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json

@@ -1,7 +1,6 @@
 [
     "======== Resolving module 'folder2/file1' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'folder2/file1'.",
     "'paths' option is specified, looking for a pattern to match module name 'folder2/file1'.",
     "Module name 'folder2/file1', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'folder2/file1'.",
@@ -10,7 +9,6 @@
     "======== Module name 'folder2/file1' was successfully resolved to 'c:/root/folder2/file1.ts'. ========",
     "======== Resolving module 'folder3/file2' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'folder3/file2'.",
     "'paths' option is specified, looking for a pattern to match module name 'folder3/file2'.",
     "Module name 'folder3/file2', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'folder3/file2'.",
@@ -21,7 +19,6 @@
     "======== Module name 'folder3/file2' was successfully resolved to 'c:/root/generated/folder3/file2.ts'. ========",
     "======== Resolving module 'components/file3' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'components/file3'.",
     "'paths' option is specified, looking for a pattern to match module name 'components/file3'.",
     "Module name 'components/file3', matched pattern 'components/*'.",
     "Trying substitution 'shared/components/*', candidate module location: 'shared/components/file3'.",
@@ -36,7 +33,6 @@
     "======== Module name 'components/file3' was successfully resolved to 'c:/root/shared/components/file3/index.d.ts'. ========",
     "======== Resolving module 'file4' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name 'file4'.",
     "'paths' option is specified, looking for a pattern to match module name 'file4'.",
     "Module name 'file4', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'file4'.",

tests/baselines/reference/pathMappingBasedModuleResolution7_classic.trace.json

@@ -12,7 +12,6 @@
     "======== Module name './project/file2' was successfully resolved to 'c:/root/generated/src/project/file2.ts'. ========",
     "======== Resolving module 'module3' from 'c:/root/src/file1.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'module3'.",
     "'paths' option is specified, looking for a pattern to match module name 'module3'.",
     "Module name 'module3', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'module3'.",
@@ -35,7 +34,6 @@
     "======== Module name 'module3' was successfully resolved to 'c:/module3.d.ts'. ========",
     "======== Resolving module 'module1' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'module1'.",
     "'paths' option is specified, looking for a pattern to match module name 'module1'.",
     "Module name 'module1', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'module1'.",
@@ -49,7 +47,6 @@
     "======== Module name 'module1' was successfully resolved to 'c:/shared/module1.d.ts'. ========",
     "======== Resolving module 'templates/module2' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'Classic'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'templates/module2'.",
     "'paths' option is specified, looking for a pattern to match module name 'templates/module2'.",
     "Module name 'templates/module2', matched pattern 'templates/*'.",
     "Trying substitution 'generated/src/templates/*', candidate module location: 'generated/src/templates/module2'.",

tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json

@@ -15,7 +15,6 @@
     "======== Module name './project/file2' was successfully resolved to 'c:/root/generated/src/project/file2.ts'. ========",
     "======== Resolving module 'module3' from 'c:/root/src/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'module3'.",
     "'paths' option is specified, looking for a pattern to match module name 'module3'.",
     "Module name 'module3', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'module3'.",
@@ -40,7 +39,6 @@
     "======== Module name 'module3' was successfully resolved to 'c:/node_modules/module3.d.ts'. ========",
     "======== Resolving module 'module1' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'module1'.",
     "'paths' option is specified, looking for a pattern to match module name 'module1'.",
     "Module name 'module1', matched pattern '*'.",
     "Trying substitution '*', candidate module location: 'module1'.",
@@ -61,7 +59,6 @@
     "======== Module name 'module1' was successfully resolved to 'c:/shared/module1/index.d.ts'. ========",
     "======== Resolving module 'templates/module2' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root/', using this value to resolve non-relative module name 'templates/module2'.",
     "'paths' option is specified, looking for a pattern to match module name 'templates/module2'.",
     "Module name 'templates/module2', matched pattern 'templates/*'.",
     "Trying substitution 'generated/src/templates/*', candidate module location: 'generated/src/templates/module2'.",

tests/baselines/reference/pathMappingBasedModuleResolution8_classic.trace.json

@@ -1,7 +1,6 @@
 [
     "======== Resolving module '@speedy/folder1/testing' from 'c:/root/index.ts'. ========",
     "Explicitly specified module resolution kind: 'Classic'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name '@speedy/folder1/testing'.",
     "'paths' option is specified, looking for a pattern to match module name '@speedy/folder1/testing'.",
     "Module name '@speedy/folder1/testing', matched pattern '@speedy/*/testing'.",
     "Trying substitution '*/dist/index.ts', candidate module location: 'folder1/dist/index.ts'.",

tests/baselines/reference/pathMappingBasedModuleResolution8_node.trace.json

@@ -1,7 +1,6 @@
 [
     "======== Resolving module '@speedy/folder1/testing' from 'c:/root/index.ts'. ========",
     "Explicitly specified module resolution kind: 'NodeJs'.",
-    "'baseUrl' option is set to 'c:/root', using this value to resolve non-relative module name '@speedy/folder1/testing'.",
     "'paths' option is specified, looking for a pattern to match module name '@speedy/folder1/testing'.",
     "Module name '@speedy/folder1/testing', matched pattern '@speedy/*/testing'.",
     "Trying substitution '*/dist/index.ts', candidate module location: 'folder1/dist/index.ts'.",

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot.js

@@ -0,0 +1,26 @@
+//// [tests/cases/compiler/pathMappingBasedModuleResolution_rootImport_aliasWithRoot.ts] ////
+
+//// [foo.ts]
+export function foo() {}
+
+//// [bar.js]
+export function bar() {}
+
+//// [a.ts]
+import { foo } from "/foo";
+import { bar } from "/bar";
+
+
+//// [foo.js]
+"use strict";
+exports.__esModule = true;
+function foo() { }
+exports.foo = foo;
+//// [bar.js]
+"use strict";
+exports.__esModule = true;
+function bar() { }
+exports.bar = bar;
+//// [a.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot.symbols

@@ -0,0 +1,15 @@
+=== /root/a.ts ===
+import { foo } from "/foo";
+>foo : Symbol(foo, Decl(a.ts, 0, 8))
+
+import { bar } from "/bar";
+>bar : Symbol(bar, Decl(a.ts, 1, 8))
+
+=== /root/src/foo.ts ===
+export function foo() {}
+>foo : Symbol(foo, Decl(foo.ts, 0, 0))
+
+=== /root/src/bar.js ===
+export function bar() {}
+>bar : Symbol(bar, Decl(bar.js, 0, 0))
+