match leading slash imports with path mappings - fixes #13730

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 +741,17 @@ namespace ts {
         }
     }
 
+    function tryLoadModuleUsingPathsIfEligible(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, state: ModuleResolutionState) {
+        const { baseUrl, paths } = state.compilerOptions;
+        if (baseUrl && paths && !pathIsRelative(moduleName)) {
+            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);
+                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 tryLoadModuleUsingRootDirs(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
         state: ModuleResolutionState): Resolved | undefined {
 
@@ -816,22 +830,13 @@ 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

@@ -247,19 +247,9 @@ 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);
-            }
-            else {
-                return getCompletionEntriesForDirectoryFragment(literalValue, scriptDirectory, extensionOptions, host, scriptPath);
-            }
-        }
-        else {
-            return getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, compilerOptions, host, typeChecker);
-        }
+        return isPathRelativeToScript(literalValue) || !compilerOptions.baseUrl && (isRootedDiskPath(literalValue) || isUrl(literalValue))
+            ? getCompletionEntriesForRelativeModules(literalValue, scriptDirectory, compilerOptions, host, scriptPath)
+            : getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, compilerOptions, host, typeChecker);
     }
 
     interface ExtensionOptions {
@@ -269,6 +259,17 @@ 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/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))
+

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot.trace.json

@@ -0,0 +1,34 @@
+[
+    "======== Resolving module '/foo' from '/root/a.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "'baseUrl' option is set to '/root', using this value to resolve non-relative module name '/foo'.",
+    "'paths' option is specified, looking for a pattern to match module name '/foo'.",
+    "Module name '/foo', matched pattern '/*'.",
+    "Trying substitution './src/*', candidate module location: './src/foo'.",
+    "Loading module as file / folder, candidate module location '/root/src/foo', target file type 'TypeScript'.",
+    "File '/root/src/foo.ts' exist - use it as a name resolution result.",
+    "======== Module name '/foo' was successfully resolved to '/root/src/foo.ts'. ========",
+    "======== Resolving module '/bar' from '/root/a.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "'baseUrl' option is set to '/root', using this value to resolve non-relative module name '/bar'.",
+    "'paths' option is specified, looking for a pattern to match module name '/bar'.",
+    "Module name '/bar', matched pattern '/*'.",
+    "Trying substitution './src/*', candidate module location: './src/bar'.",
+    "Loading module as file / folder, candidate module location '/root/src/bar', target file type 'TypeScript'.",
+    "File '/root/src/bar.ts' does not exist.",
+    "File '/root/src/bar.tsx' does not exist.",
+    "File '/root/src/bar.d.ts' does not exist.",
+    "Directory '/root/src/bar' does not exist, skipping all lookups in it.",
+    "Loading module as file / folder, candidate module location '/bar', target file type 'TypeScript'.",
+    "File '/bar.ts' does not exist.",
+    "File '/bar.tsx' does not exist.",
+    "File '/bar.d.ts' does not exist.",
+    "Directory '/bar' does not exist, skipping all lookups in it.",
+    "'baseUrl' option is set to '/root', using this value to resolve non-relative module name '/bar'.",
+    "'paths' option is specified, looking for a pattern to match module name '/bar'.",
+    "Module name '/bar', matched pattern '/*'.",
+    "Trying substitution './src/*', candidate module location: './src/bar'.",
+    "Loading module as file / folder, candidate module location '/root/src/bar', target file type 'JavaScript'.",
+    "File '/root/src/bar.js' exist - use it as a name resolution result.",
+    "======== Module name '/bar' was successfully resolved to '/root/src/bar.js'. ========"
+]

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot.types

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

tests/baselines/reference/pathMappingBasedModuleResolution_rootImport_aliasWithRoot_differentRootTypes.js

@@ -0,0 +1,42 @@
+//// [tests/cases/compiler/pathMappingBasedModuleResolution_rootImport_aliasWithRoot_differentRootTypes.ts] ////
+
+//// [foo.ts]
+export function foo() {}
+
+//// [bar.js]
+export function bar() {}
+
+//// [a.ts]
+import { foo as foo1 } from "/foo";
+import { bar as bar1 } from "/bar";
+import { foo as foo2 } from "c:/foo";
+import { bar as bar2 } from "c:/bar";
+import { foo as foo3 } from "c:\\foo";
+import { bar as bar3 } from "c:\\bar";
+import { foo as foo4 } from "//server/foo";
+import { bar as bar4 } from "//server/bar";
+import { foo as foo5 } from "\\\\server\\foo";
+import { bar as bar5 } from "\\\\server\\bar";
+import { foo as foo6 } from "file:///foo";
+import { bar as bar6 } from "file:///bar";
+import { foo as foo7 } from "file://c:/foo";
+import { bar as bar7 } from "file://c:/bar";
+import { foo as foo8 } from "file://server/foo";
+import { bar as bar8 } from "file://server/bar";
+import { foo as foo9 } from "http://server/foo";
+import { bar as bar9 } from "http://server/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_differentRootTypes.symbols

@@ -0,0 +1,81 @@
+=== /root/a.ts ===
+import { foo as foo1 } from "/foo";
+>foo : Symbol(foo1, Decl(a.ts, 0, 8))
+>foo1 : Symbol(foo1, Decl(a.ts, 0, 8))
+
+import { bar as bar1 } from "/bar";
+>bar : Symbol(bar1, Decl(a.ts, 1, 8))
+>bar1 : Symbol(bar1, Decl(a.ts, 1, 8))
+
+import { foo as foo2 } from "c:/foo";
+>foo : Symbol(foo2, Decl(a.ts, 2, 8))
+>foo2 : Symbol(foo2, Decl(a.ts, 2, 8))
+
+import { bar as bar2 } from "c:/bar";
+>bar : Symbol(bar2, Decl(a.ts, 3, 8))
+>bar2 : Symbol(bar2, Decl(a.ts, 3, 8))
+
+import { foo as foo3 } from "c:\\foo";
+>foo : Symbol(foo3, Decl(a.ts, 4, 8))
+>foo3 : Symbol(foo3, Decl(a.ts, 4, 8))
+
+import { bar as bar3 } from "c:\\bar";
+>bar : Symbol(bar3, Decl(a.ts, 5, 8))
+>bar3 : Symbol(bar3, Decl(a.ts, 5, 8))
+
+import { foo as foo4 } from "//server/foo";
+>foo : Symbol(foo4, Decl(a.ts, 6, 8))
+>foo4 : Symbol(foo4, Decl(a.ts, 6, 8))
+
+import { bar as bar4 } from "//server/bar";
+>bar : Symbol(bar4, Decl(a.ts, 7, 8))
+>bar4 : Symbol(bar4, Decl(a.ts, 7, 8))
+
+import { foo as foo5 } from "\\\\server\\foo";
+>foo : Symbol(foo5, Decl(a.ts, 8, 8))
+>foo5 : Symbol(foo5, Decl(a.ts, 8, 8))
+
+import { bar as bar5 } from "\\\\server\\bar";
+>bar : Symbol(bar5, Decl(a.ts, 9, 8))
+>bar5 : Symbol(bar5, Decl(a.ts, 9, 8))
+
+import { foo as foo6 } from "file:///foo";
+>foo : Symbol(foo6, Decl(a.ts, 10, 8))
+>foo6 : Symbol(foo6, Decl(a.ts, 10, 8))
+
+import { bar as bar6 } from "file:///bar";
+>bar : Symbol(bar6, Decl(a.ts, 11, 8))
+>bar6 : Symbol(bar6, Decl(a.ts, 11, 8))
+
+import { foo as foo7 } from "file://c:/foo";
+>foo : Symbol(foo7, Decl(a.ts, 12, 8))
+>foo7 : Symbol(foo7, Decl(a.ts, 12, 8))
+
+import { bar as bar7 } from "file://c:/bar";
+>bar : Symbol(bar7, Decl(a.ts, 13, 8))
+>bar7 : Symbol(bar7, Decl(a.ts, 13, 8))
+
+import { foo as foo8 } from "file://server/foo";
+>foo : Symbol(foo8, Decl(a.ts, 14, 8))
+>foo8 : Symbol(foo8, Decl(a.ts, 14, 8))
+
+import { bar as bar8 } from "file://server/bar";
+>bar : Symbol(bar8, Decl(a.ts, 15, 8))
+>bar8 : Symbol(bar8, Decl(a.ts, 15, 8))
+
+import { foo as foo9 } from "http://server/foo";
+>foo : Symbol(foo9, Decl(a.ts, 16, 8))
+>foo9 : Symbol(foo9, Decl(a.ts, 16, 8))
+
+import { bar as bar9 } from "http://server/bar";
+>bar : Symbol(bar9, Decl(a.ts, 17, 8))
+>bar9 : Symbol(bar9, Decl(a.ts, 17, 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))
+