Add support for Call Hierarchies in language server (#35176)

* Add support for Call Hierarchies in language server

* Use baselines for callHierarchy tests

* Clean up commented code

* Support multiple hierarchy items when an implementation can't be found

* Use optional chaining in a few places

* Use getFileAndProject

tests/cases/fourslash/callHierarchyAccessor.ts

@@ -0,0 +1,17 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     new C().bar;
+//// }
+////
+//// class C {
+////     get /**/bar() {
+////         return baz();
+////     }
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyClass.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     bar();
+//// }
+////
+//// function /**/bar() {
+////     new Baz();
+//// }
+////
+//// class Baz {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyConstNamedArrowFunction.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     bar();
+//// }
+////
+//// const /**/bar = () => {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyConstNamedClassExpression.ts

@@ -0,0 +1,17 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     new Bar();
+//// }
+////
+//// const /**/Bar = class {
+////     constructor() {
+////         baz();
+////     }
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyConstNamedFunctionExpression.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     bar();
+//// }
+////
+//// const /**/bar = function () {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyDecorator.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @experimentalDecorators: true
+//// @bar
+//// class Foo {
+//// }
+////
+//// function /**/bar() {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyExportDefaultClass.ts

@@ -0,0 +1,21 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: main.ts
+//// import Bar from "./other";
+////
+//// function foo() {
+////     new Bar();
+//// }
+
+// @filename: other.ts
+//// export /**/default class {
+////     constructor() {
+////         baz();
+////     }
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyExportDefaultFunction.ts

@@ -0,0 +1,19 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: main.ts
+//// import bar from "./other";
+////
+//// function foo() {
+////     bar();
+//// }
+
+// @filename: other.ts
+//// export /**/default function () {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyExportEqualsFunction.ts

@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: main.ts
+//// import bar = require("./other");
+////
+//// function foo() {
+////     bar();
+//// }
+
+// @filename: other.ts
+//// export = /**/function () {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+// NOTE: exported function is unnamed, so we expand the item to the entire file...
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFile.ts

@@ -0,0 +1,8 @@
+/// <reference path="fourslash.ts" />
+
+//// foo();
+//// function /**/foo() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunction.ts

@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     bar();
+//// }
+////
+//// function /**/bar() {
+////     baz();
+////     quxx();
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+////
+//// function quxx() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunctionAmbiguity.1.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: a.d.ts
+//// declare function foo(x?: number): void;
+
+// @filename: b.d.ts
+//// declare function foo(x?: string): void;
+//// declare function foo(x?: boolean): void;
+
+// @filename: main.ts
+//// function bar() {
+////     /**/foo();
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunctionAmbiguity.2.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: a.d.ts
+//// declare function /**/foo(x?: number): void;
+
+// @filename: b.d.ts
+//// declare function foo(x?: string): void;
+//// declare function foo(x?: boolean): void;
+
+// @filename: main.ts
+//// function bar() {
+////     foo();
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunctionAmbiguity.3.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: a.d.ts
+//// declare function foo(x?: number): void;
+
+// @filename: b.d.ts
+//// declare function /**/foo(x?: string): void;
+//// declare function foo(x?: boolean): void;
+
+// @filename: main.ts
+//// function bar() {
+////     foo();
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunctionAmbiguity.4.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: a.d.ts
+//// declare function foo(x?: number): void;
+
+// @filename: b.d.ts
+//// declare function foo(x?: string): void;
+//// declare function /**/foo(x?: boolean): void;
+
+// @filename: main.ts
+//// function bar() {
+////     foo();
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyFunctionAmbiguity.5.ts

@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: a.d.ts
+//// declare function foo(x?: number): void;
+
+// @filename: b.d.ts
+//// declare function foo(x?: string): void;
+//// declare function foo(x?: boolean): void;
+
+// @filename: main.ts
+//// function /**/bar() {
+////     foo();
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyInterfaceMethod.ts

@@ -0,0 +1,12 @@
+/// <reference path="fourslash.ts" />
+
+//// interface I {
+////     /**/foo(): void;
+//// }
+////
+//// const obj: I = { foo() {} };
+////
+//// obj.foo();
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyJsxElement.ts

@@ -0,0 +1,17 @@
+/// <reference path="fourslash.ts" />
+
+// @jsx: preserve
+// @filename: main.tsx
+//// function foo() {
+////     return <Bar/>;
+//// }
+////
+//// function /**/Bar() {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/callHierarchyTaggedTemplate.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+//// function foo() {
+////     bar`a${1}b`;
+//// }
+////
+//// function /**/bar(array: TemplateStringsArray, ...args: any[]) {
+////     baz();
+//// }
+////
+//// function baz() {
+//// }
+
+goTo.marker();
+verify.baselineCallHierarchy();

tests/cases/fourslash/fourslash.ts

@@ -383,6 +383,7 @@ declare namespace FourSlashInterface {
             readonly newFileContents: { readonly [fileName: string]: string };
             readonly preferences?: UserPreferences;
         }): void;
+        baselineCallHierarchy(): void;
         moveToNewFile(options: {
             readonly newFileContents: { readonly [fileName: string]: string };
             readonly preferences?: UserPreferences;
@@ -773,4 +774,4 @@ declare namespace completion {
     export const statementKeywordsWithTypes: ReadonlyArray<Entry>;
     export const statementKeywords: ReadonlyArray<Entry>;
     export const statementInJsKeywords: ReadonlyArray<Entry>;
-}
+}