fix(hover): correct hover information for type signatures with callbacks (#415)

Fixes #413

Author: Dan Rosén

src/test/typescript-service-helpers.ts

@@ -124,6 +124,10 @@ export function describeTypeScriptService(
                     [rootUri + 'foo/b.ts', ['/* This is class Foo */', 'export class Foo {}'].join('\n')],
                     [rootUri + 'foo/c.ts', 'import {Foo} from "./b";'],
                     [rootUri + 'd.ts', ['export interface I {', '  target: string;', '}'].join('\n')],
+                    [
+                        rootUri + 'local_callback.ts',
+                        'function local(): void { function act(handle: () => void): void { handle() } }',
+                    ],
                     [
                         rootUri + 'e.ts',
                         [
@@ -322,6 +326,38 @@ export function describeTypeScriptService(
                     contents: [{ language: 'typescript', value: 'const abc: 1' }, '**const**'],
                 })
             })
+            specify('local function with callback argument', async function(
+                this: TestContext & ITestCallbackContext
+            ): Promise<void> {
+                const result: Hover = await this.service
+                    .textDocumentHover({
+                        textDocument: {
+                            uri: rootUri + 'local_callback.ts',
+                        },
+                        position: {
+                            line: 0,
+                            character: 36,
+                        },
+                    })
+                    .reduce<Operation, Hover>(applyReducer, null as any)
+                    .toPromise()
+                assert.deepEqual(result, {
+                    range: {
+                        start: {
+                            line: 0,
+                            character: 34,
+                        },
+                        end: {
+                            line: 0,
+                            character: 37,
+                        },
+                    },
+                    contents: [
+                        { language: 'typescript', value: 'act(handle: () => void): void' },
+                        '**local function**',
+                    ],
+                })
+            })
             specify('in other file', async function(this: TestContext & ITestCallbackContext): Promise<void> {
                 const result: Hover = await this.service
                     .textDocumentHover({

src/typescript-service.ts

@@ -609,7 +609,7 @@ export class TypeScriptService {
                 }
                 const contents: (MarkedString | string)[] = []
                 // Add declaration without the kind
-                const declaration = ts.displayPartsToString(info.displayParts).replace(/^\(.+\)\s+/, '')
+                const declaration = ts.displayPartsToString(info.displayParts).replace(/^\(.+?\)\s+/, '')
                 contents.push({ language: 'typescript', value: declaration })
                 // Add kind with modifiers, e.g. "method (private, ststic)", "class (exported)"
                 if (info.kind) {