Find references of a module by filename (#41805)

* Naive implementation enough to build and write a test

* Add simple test

* Add project references test

* Add deduplication test, accept baselines

* Add test for referencing a script (doesn’t do anything)

* Update API baselines

* Use refFileMap for non-module references

* Fix find-all-refs on module specifier

* Remove unused util

* Don’t store text range on ts.RefFile

* Ensure string literal could itself be a file reference

* Remove unused utilities

* Improve baseline format

* Preserve old behavior of falling back to string literal references

* Update baselines from master

* Fix old RefFileMap code after merge

* Add test for additional response info

* Undo test change

src/testRunner/tsconfig.json

@@ -171,6 +171,7 @@
         "unittests/tsserver/getApplicableRefactors.ts",
         "unittests/tsserver/getEditsForFileRename.ts",
         "unittests/tsserver/getExportReferences.ts",
+        "unittests/tsserver/getFileReferences.ts",
         "unittests/tsserver/importHelpers.ts",
         "unittests/tsserver/importSuggestionsCache.ts",
         "unittests/tsserver/inferredProjects.ts",

src/testRunner/unittests/tsserver/getFileReferences.ts

@@ -0,0 +1,58 @@
+namespace ts.projectSystem {
+    describe("unittests:: tsserver:: getFileReferences", () => {
+        const importA = `import "./a";`;
+        const importCurlyFromA = `import {} from "./a";`;
+        const importAFromA = `import { a } from "/project/a";`;
+        const typeofImportA = `type T = typeof import("./a").a;`;
+
+        const aTs: File = {
+            path: "/project/a.ts",
+            content: "export const a = {};",
+        };
+        const bTs: File = {
+            path: "/project/b.ts",
+            content: importA,
+        };
+        const cTs: File = {
+            path: "/project/c.ts",
+            content: importCurlyFromA
+        };
+        const dTs: File = {
+            path: "/project/d.ts",
+            content: [importAFromA, typeofImportA].join("\n")
+        };
+        const tsconfig: File = {
+            path: "/project/tsconfig.json",
+            content: "{}",
+        };
+
+        function makeSampleSession() {
+            const host = createServerHost([aTs, bTs, cTs, dTs, tsconfig]);
+            const session = createSession(host);
+            openFilesForSession([aTs, bTs, cTs, dTs], session);
+            return session;
+        }
+
+        it("should get file references", () => {
+            const session = makeSampleSession();
+
+            const response = executeSessionRequest<protocol.FileReferencesRequest, protocol.FileReferencesResponse>(
+                session,
+                protocol.CommandTypes.FileReferences,
+                { file: aTs.path },
+            );
+
+            const expectResponse: protocol.FileReferencesResponseBody = {
+                refs: [
+                    makeReferenceItem({ file: bTs, text: "./a", lineText: importA, contextText: importA, isDefinition: false, isWriteAccess: false }),
+                    makeReferenceItem({ file: cTs, text: "./a", lineText: importCurlyFromA, contextText: importCurlyFromA, isDefinition: false, isWriteAccess: false }),
+                    makeReferenceItem({ file: dTs, text: "/project/a", lineText: importAFromA, contextText: importAFromA, isDefinition: false, isWriteAccess: false }),
+                    makeReferenceItem({ file: dTs, text: "./a", lineText: typeofImportA, contextText: typeofImportA, isDefinition: false, isWriteAccess: false }),
+                ],
+                symbolName: `"${aTs.path}"`,
+            };
+
+            assert.deepEqual(response, expectResponse);
+        });
+    });
+}

src/testRunner/unittests/tsserver/session.ts

@@ -207,6 +207,8 @@ namespace ts.server {
                 CommandNames.Implementation,
                 CommandNames.ImplementationFull,
                 CommandNames.Exit,
+                CommandNames.FileReferences,
+                CommandNames.FileReferencesFull,
                 CommandNames.Format,
                 CommandNames.Formatonkey,
                 CommandNames.FormatFull,