9 files changed, 232 insertions, 0 deletions
diff --git a/packages/turbo-test-utils/README.md b/packages/turbo-test-utils/README.md
new file mode 100644
index 0000000..60b6382
--- /dev/null
+++ b/packages/turbo-test-utils/README.md
@@ -0,0 +1,3 @@
+# `@turbo/test-utils`
+
+Internal package of generic testing utilities shared between [turborepo/packages/](https://github.com/vercel/turbo/tree/main/packages)
diff --git a/packages/turbo-test-utils/package.json b/packages/turbo-test-utils/package.json
new file mode 100644
index 0000000..ff3f7f9
--- /dev/null
+++ b/packages/turbo-test-utils/package.json
@@ -0,0 +1,40 @@
+{
+  "name": "@turbo/test-utils",
+  "version": "0.0.0",
+  "private": true,
+  "description": "",
+  "homepage": "https://turbo.build/repo",
+  "keywords": [],
+  "author": "Vercel",
+  "main": "src/index.ts",
+  "license": "MPL-2.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/vercel/turbo",
+    "directory": "packages/turbo-test-utils"
+  },
+  "bugs": {
+    "url": "https://github.com/vercel/turbo/issues"
+  },
+  "scripts": {
+    "lint": "eslint src/**/*.ts",
+    "check-types": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "@types/fs-extra": "^9.0.13",
+    "@types/jest": "^27.4.0",
+    "@types/js-yaml": "^4.0.5",
+    "@types/node": "^16.11.12",
+    "@types/uuid": "^9.0.0",
+    "jest": "^27.4.3",
+    "ts-jest": "^27.1.1",
+    "@turbo/tsconfig": "workspace:*",
+    "typescript": "^4.7.4"
+  },
+  "dependencies": {
+    "fs-extra": "^11.1.0",
+    "js-yaml": "^4.1.0",
+    "json5": "^2.2.3",
+    "uuid": "^9.0.0"
+  }
+}
diff --git a/packages/turbo-test-utils/src/index.ts b/packages/turbo-test-utils/src/index.ts
new file mode 100644
index 0000000..07d0496
--- /dev/null
+++ b/packages/turbo-test-utils/src/index.ts
@@ -0,0 +1,9 @@
+export { default as setupTestFixtures } from "./useFixtures";
+export { default as validateLogs } from "./validateLogs";
+export { default as mockEnv } from "./mockEnv";
+
+export { default as spyExit } from "./spyExit";
+export type { SpyExit } from "./spyExit";
+
+export { default as spyConsole } from "./spyConsole";
+export type { SpyConsole } from "./spyConsole";
diff --git a/packages/turbo-test-utils/src/mockEnv.ts b/packages/turbo-test-utils/src/mockEnv.ts
new file mode 100644
index 0000000..31909b0
--- /dev/null
+++ b/packages/turbo-test-utils/src/mockEnv.ts
@@ -0,0 +1,12 @@
+export default function mockEnv() {
+  const OLD_ENV = process.env;
+
+  beforeEach(() => {
+    jest.resetModules();
+    process.env = { ...OLD_ENV };
+  });
+
+  afterAll(() => {
+    process.env = OLD_ENV;
+  });
+}
diff --git a/packages/turbo-test-utils/src/spyConsole.ts b/packages/turbo-test-utils/src/spyConsole.ts
new file mode 100644
index 0000000..61722a5
--- /dev/null
+++ b/packages/turbo-test-utils/src/spyConsole.ts
@@ -0,0 +1,25 @@
+export type SpyConsole = { log?: any; error?: any; warn?: any };
+
+export default function spyConsole() {
+  let spy: SpyConsole = {};
+
+  beforeEach(() => {
+    spy.log = jest.spyOn(console, "log").mockImplementation(() => {});
+    spy.error = jest.spyOn(console, "error").mockImplementation(() => {});
+    spy.warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    spy.log.mockClear();
+    spy.error.mockClear();
+    spy.warn.mockClear();
+  });
+
+  afterAll(() => {
+    spy.log.mockRestore();
+    spy.error.mockRestore();
+    spy.warn.mockRestore();
+  });
+
+  return spy;
+}
diff --git a/packages/turbo-test-utils/src/spyExit.ts b/packages/turbo-test-utils/src/spyExit.ts
new file mode 100644
index 0000000..1df9844
--- /dev/null
+++ b/packages/turbo-test-utils/src/spyExit.ts
@@ -0,0 +1,21 @@
+export type SpyExit = { exit?: any };
+
+export default function spyExit() {
+  let spy: SpyExit = {};
+
+  beforeEach(() => {
+    spy.exit = jest
+      .spyOn(process, "exit")
+      .mockImplementation(() => undefined as never);
+  });
+
+  afterEach(() => {
+    spy.exit.mockClear();
+  });
+
+  afterAll(() => {
+    spy.exit.mockRestore();
+  });
+
+  return spy;
+}
diff --git a/packages/turbo-test-utils/src/useFixtures.ts b/packages/turbo-test-utils/src/useFixtures.ts
new file mode 100644
index 0000000..2c47f5a
--- /dev/null
+++ b/packages/turbo-test-utils/src/useFixtures.ts
@@ -0,0 +1,89 @@
+import { v4 as uuidv4 } from "uuid";
+import path from "path";
+import fs from "fs-extra";
+import yaml from "js-yaml";
+import JSON5 from "json5";
+
+export default function setupTestFixtures({
+  directory,
+  test = "",
+}: {
+  directory: string;
+  test?: string;
+}) {
+  const fixtures: Array<string> = [];
+  const parentDirectory = path.join(directory, test ? test : "test-runs");
+
+  afterEach(() => {
+    fixtures.forEach((fixture) => {
+      fs.rmSync(fixture, { recursive: true, force: true });
+    });
+  });
+
+  afterAll(() => {
+    fs.rmSync(parentDirectory, { recursive: true, force: true });
+  });
+
+  const useFixture = ({ fixture }: { fixture: string }) => {
+    const directoryName = uuidv4();
+    const testDirectory = path.join(parentDirectory, directoryName);
+    if (!fs.existsSync(testDirectory)) {
+      fs.mkdirSync(testDirectory, { recursive: true });
+    }
+    // keep track of it
+    fixtures.push(testDirectory);
+
+    // copy fixture to test directory
+    const fixturePath = path.join(directory, "__fixtures__", test, fixture);
+    fs.copySync(fixturePath, testDirectory, {
+      recursive: true,
+    });
+
+    const getFilePath = (filename: string) => {
+      return path.isAbsolute(filename)
+        ? filename
+        : path.join(testDirectory, filename);
+    };
+
+    const readGenerator = (method: (filePath: string) => unknown) => {
+      return <T>(filename: string) => {
+        try {
+          return method(getFilePath(filename)) as T;
+        } catch (e) {
+          return undefined;
+        }
+      };
+    };
+
+    const write = (
+      filename: string,
+      content: string | NodeJS.ArrayBufferView
+    ) => {
+      fs.writeFileSync(getFilePath(filename), content);
+    };
+
+    const exists = (filename: string): boolean => {
+      return fs.existsSync(getFilePath(filename));
+    };
+
+    const read = readGenerator((filePath) => fs.readFileSync(filePath, "utf8"));
+    const readJson = readGenerator((filePath) =>
+      JSON5.parse(fs.readFileSync(filePath, "utf8"))
+    );
+    const readYaml = readGenerator((filePath) =>
+      yaml.load(fs.readFileSync(filePath, "utf8"))
+    );
+
+    return {
+      root: testDirectory,
+      read,
+      readJson,
+      readYaml,
+      write,
+      exists,
+      directoryName,
+    };
+  };
+
+  return { useFixture };
+}
diff --git a/packages/turbo-test-utils/src/validateLogs.ts b/packages/turbo-test-utils/src/validateLogs.ts
new file mode 100644
index 0000000..b8e59ac
--- /dev/null
+++ b/packages/turbo-test-utils/src/validateLogs.ts
@@ -0,0 +1,27 @@
+import { SpyConsole } from "./spyConsole";
+
+export default function validateLogs(
+  logs: Array<string | (() => boolean | Array<any>)>,
+  mockConsole: SpyConsole["log"] | SpyConsole["error"],
+  options: { prefix?: string } = {}
+) {
+  logs.forEach((log, idx) => {
+    if (typeof log === "function") {
+      const expected = log();
+      expect(mockConsole).toHaveBeenNthCalledWith(
+        idx + 1,
+        ...(Array.isArray(expected) ? expected : [expected])
+      );
+    } else {
+      if (options.prefix) {
+        expect(mockConsole).toHaveBeenNthCalledWith(
+          idx + 1,
+          options.prefix,
+          log
+        );
+      } else {
+        expect(mockConsole).toHaveBeenNthCalledWith(idx + 1, log);
+      }
+    }
+  });
+}
diff --git a/packages/turbo-test-utils/tsconfig.json b/packages/turbo-test-utils/tsconfig.json
new file mode 100644
index 0000000..0620a3c
--- /dev/null
+++ b/packages/turbo-test-utils/tsconfig.json
@@ -0,0 +1,6 @@
+{
+  "extends": "@turbo/tsconfig/library.json",
+  "compilerOptions": {
+    "rootDir": "."
+  }
+}