replace whole path if directory separator appears for import completion. (#41412)

* replace whole path if directory separator appears.

* Fix.

* revert change.

* Fix test case.

* add test.

* fix as suggested.

* revert useless change

* adapt to code change.

* fix baseline for test file.

src/compiler/path.ts

@@ -6,7 +6,7 @@ namespace ts {
      * we expect the host to correctly handle paths in our specified format.
      */
     export const directorySeparator = "/";
-    const altDirectorySeparator = "\\";
+    export const altDirectorySeparator = "\\";
     const urlSchemeSeparator = "://";
     const backslashRegExp = /\\/g;
 

src/services/stringCompletions.ts

@@ -279,7 +279,9 @@ namespace ts.Completions.StringCompletions {
 
     function addReplacementSpans(text: string, textStart: number, names: readonly NameAndKind[]): readonly PathCompletion[] {
         const span = getDirectoryFragmentTextSpan(text, textStart);
-        return names.map(({ name, kind, extension }): PathCompletion => ({ name, kind, extension, span }));
+        const wholeSpan = text.length === 0 ? undefined : createTextSpan(textStart, text.length);
+        return names.map(({ name, kind, extension }): PathCompletion =>
+            Math.max(name.indexOf(directorySeparator), name.indexOf(altDirectorySeparator)) !== -1 ? { name, kind, extension, span: wholeSpan } : { name, kind, extension, span });
     }
 
     function getStringLiteralCompletionsFromModuleNames(sourceFile: SourceFile, node: LiteralExpression, compilerOptions: CompilerOptions, host: LanguageServiceHost, typeChecker: TypeChecker): readonly PathCompletion[] {
@@ -683,7 +685,7 @@ namespace ts.Completions.StringCompletions {
 
     // Replace everything after the last directory separator that appears
     function getDirectoryFragmentTextSpan(text: string, textStart: number): TextSpan | undefined {
-        const index = Math.max(text.lastIndexOf(directorySeparator), text.lastIndexOf("\\"));
+        const index = Math.max(text.lastIndexOf(directorySeparator), text.lastIndexOf(altDirectorySeparator));
         const offset = index !== -1 ? index + 1 : 0;
         // If the range is an identifier, span is unnecessary.
         const length = text.length - offset;

tests/cases/fourslash/completionForStringLiteralNonrelativeImport14.ts

@@ -25,4 +25,69 @@
 // @Filename: some/other/path.ts
 //// export var y = 10;
 
-verify.completions({ marker: test.markerNames(), exact: ["lib", "tests", "/module1", "/module2"], isNewIdentifierLocation: true });
+verify.completions({
+    marker: ["import_as0",],
+    exact: ["lib", "tests",
+        {
+            name: "/module1",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 23,
+                end: 24
+            }
+        },
+        {
+            name: "/module2",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 23,
+                end: 24
+            }
+        }],
+    isNewIdentifierLocation: true
+});
+
+
+verify.completions({
+    marker: ["import_equals0",],
+    exact: ["lib", "tests",
+        {
+            name: "/module1",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 48,
+                end: 49
+            }
+        },
+        {
+            name: "/module2",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 48,
+                end: 49
+            }
+        }],
+    isNewIdentifierLocation: true
+});
+
+verify.completions({
+    marker: ["require0",],
+    exact: ["lib", "tests",
+        {
+            name: "/module1",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 70,
+                end: 71
+            }
+        },
+        {
+            name: "/module2",
+            replacementSpan: {
+                fileName: "foo",
+                pos: 70,
+                end: 71
+            }
+        }],
+    isNewIdentifierLocation: true
+});

tests/cases/fourslash/completionForStringLiteralNonrelativeImport16.ts

@@ -0,0 +1,40 @@
+/// <reference path='fourslash.ts' />
+
+// Should give completions for modules referenced via baseUrl and paths compiler options with explicit name mappings
+
+// @Filename: tsconfig.json
+//// {
+////     "compilerOptions": {
+////         "baseUrl": "./",
+////         "paths": {
+////             "module1/path1": ["some/path/whatever.ts"],
+////         }
+////     }
+//// }
+
+// @Filename: test0.ts
+//// import * as foo1 from "m/*first*/
+//// import * as foo1 from "module1/pa/*second*/
+
+// @Filename: some/path/whatever.ts
+//// export var x = 9;
+
+verify.completions({ marker: ["first"], exact: ["test0", "some", {
+    name: "module1/path1",
+    replacementSpan: {
+        fileName: "foo",
+        pos: 23,
+        end: 24
+    }
+}], isNewIdentifierLocation: true });
+
+verify.completions({
+    marker: ["second"], exact: [{
+        name: "module1/path1",
+        replacementSpan: {
+            fileName: "foo",
+            pos: 48,
+            end: 58
+        }
+    }], isNewIdentifierLocation: true
+});