From b063c3dcf85d90f58b55e1a0a525d69fd346c7bf Mon Sep 17 00:00:00 2001
From: Sehsyha <valentin.stern@gmail.com>
Date: Thu, 17 Oct 2019 10:00:42 +0200
Subject: [PATCH] feat: add golang language detector

Fixes #82
---
 .../Golang/GolangLanguageDetector.spec.ts     | 60 +++++++++++++++++++
 .../Golang/GolangLanguageDetector.ts          | 37 ++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 src/detectors/Golang/GolangLanguageDetector.spec.ts
 create mode 100644 src/detectors/Golang/GolangLanguageDetector.ts

diff --git a/src/detectors/Golang/GolangLanguageDetector.spec.ts b/src/detectors/Golang/GolangLanguageDetector.spec.ts
new file mode 100644
index 000000000..3d4c7a412
--- /dev/null
+++ b/src/detectors/Golang/GolangLanguageDetector.spec.ts
@@ -0,0 +1,60 @@
+import { FileInspector } from '../../inspectors/FileInspector';
+import { ProgrammingLanguage } from '../../model';
+import { FileSystemService } from '../../services/FileSystemService';
+import * as nodePath from 'path';
+import { DirectoryJSON } from 'memfs/lib/volume';
+import { GolangLanguageDetector } from './GolangLanguageDetector';
+
+describe('GolangLanguageDetector', () => {
+  let detector: GolangLanguageDetector;
+  let virtualFileSystemService: FileSystemService;
+
+  beforeEach(() => {
+    virtualFileSystemService = new FileSystemService({ isVirtual: true });
+
+    const fileInspector = new FileInspector(virtualFileSystemService, '/');
+    detector = new GolangLanguageDetector(fileInspector);
+  });
+
+  afterEach(async () => {
+    virtualFileSystemService.clearFileSystem();
+  });
+
+  it('detects golang correctly via Gopkg.toml', async () => {
+    const structure: DirectoryJSON = {
+      '/Gopkg.toml': '...',
+    };
+
+    virtualFileSystemService.setFileSystem(structure);
+
+    const langAtPath = await detector.detectLanguage();
+    expect(langAtPath.length).toEqual(1);
+    expect(langAtPath[0].language).toEqual(ProgrammingLanguage.Go);
+    expect(langAtPath[0].path).toEqual(nodePath.sep);
+  });
+
+  it("detects it's not a golang file", async () => {
+    const structure: DirectoryJSON = {
+      '/src/index.none': '...',
+    };
+
+    virtualFileSystemService.setFileSystem(structure);
+
+    const langAtPath = await detector.detectLanguage();
+    expect(langAtPath.length).toEqual(0);
+    expect(langAtPath).toEqual([]);
+  });
+
+  it('detects golang correctly via go file', async () => {
+    const structure: DirectoryJSON = {
+      '/index.go': '...',
+    };
+
+    virtualFileSystemService.setFileSystem(structure);
+
+    const langAtPath = await detector.detectLanguage();
+    expect(langAtPath.length).toEqual(1);
+    expect(langAtPath[0].language).toEqual(ProgrammingLanguage.Go);
+    expect(langAtPath[0].path).toEqual(nodePath.sep);
+  });
+});
diff --git a/src/detectors/Golang/GolangLanguageDetector.ts b/src/detectors/Golang/GolangLanguageDetector.ts
new file mode 100644
index 000000000..43b12d5c4
--- /dev/null
+++ b/src/detectors/Golang/GolangLanguageDetector.ts
@@ -0,0 +1,37 @@
+import { ILanguageDetector } from '../ILanguageDetector';
+import { injectable, inject } from 'inversify';
+import { LanguageAtPath, ProgrammingLanguage } from '../../model';
+import { IFileInspector } from '../../inspectors/IFileInspector';
+import { Types } from '../../types';
+import { fileNameRegExp, fileExtensionRegExp, sharedSubpath } from '../utils';
+import { uniq } from 'lodash';
+import * as nodePath from 'path';
+
+@injectable()
+export class GolangLanguageDetector implements ILanguageDetector {
+  private fileInspector: IFileInspector;
+  constructor(@inject(Types.IFileInspector) fileInspector: IFileInspector) {
+    this.fileInspector = fileInspector;
+  }
+
+  async detectLanguage(): Promise<LanguageAtPath[]> {
+    const result: LanguageAtPath[] = [];
+    const packageFiles = await this.fileInspector.scanFor(fileNameRegExp('Gopkg.toml'), '/');
+
+    if(packageFiles.length > 0) {
+      for (const path of packageFiles.map((file) => nodePath.dirname(file.path))) {
+        result.push({ language: ProgrammingLanguage.Go, path });
+      }
+    } else {
+      const goFiles = await this.fileInspector.scanFor(fileExtensionRegExp(['go']), '/');
+      if (goFiles.length === 0) {
+        return result;
+      }
+      const dirsWithProjects = uniq(goFiles.map((f) => nodePath.dirname(f.path)));
+      // Get the shared subpath
+      const commonPath = sharedSubpath(dirsWithProjects);
+      result.push({ language: ProgrammingLanguage.Go, path: commonPath });
+    }
+    return result;
+  }
+}