Add command unit tests

jest.config.js

@@ -29,5 +29,4 @@ module.exports = {
 
   // The glob patterns Jest uses to detect test files
   testMatch: ["**/test/**/?(*.)+(spec|test).js?(x)"]
-  //testMatch: ["**/test/link.spec.js"]
 };

src/command.js

@@ -32,6 +32,7 @@ const runAndCatch = () => {
   return run().catch(err => {
     console.log(chalk.red(`\nERROR: ${err.message}.\n`));
     process.exitCode = 1;
+    return Promise.resolve();
   });
 };
 

test/command.spec.js

@@ -0,0 +1,69 @@
+const sinon = require("sinon");
+
+const link = require("../src/link");
+const unlink = require("../src/unlink");
+const check = require("../src/check");
+
+const command = require("../src/command");
+
+describe("command", () => {
+  let sandbox;
+  let originalArgs;
+
+  beforeAll(() => {
+    originalArgs = [...process.argv];
+  });
+
+  beforeEach(() => {
+    sandbox = sinon.createSandbox();
+    sandbox.stub(link, "all").resolves();
+    sandbox.stub(link, "select").resolves();
+    sandbox.stub(unlink, "all").resolves();
+    sandbox.stub(check, "avoidFileLinks").resolves();
+  });
+
+  afterEach(() => {
+    process.argv = [...originalArgs];
+    sandbox.restore();
+  });
+
+  describe("runAndCatch method", () => {
+    it("should mark process to exit with error if command throws an error", async () => {
+      expect.assertions(2);
+      link.select.rejects(new Error("Foo error"));
+      sandbox.stub(console, "log");
+      await command.runAndCatch();
+      expect(process.exitCode).toEqual(1);
+      process.exitCode = 0;
+      expect(console.log.getCall(0).args[0]).toEqual(expect.stringContaining("Foo error"));
+    });
+
+    it("should link selected packages by default", async () => {
+      expect.assertions(1);
+      await command.runAndCatch();
+      expect(link.select.callCount).toEqual(1);
+    });
+
+    it("should link all packages if --all option is received", async () => {
+      expect.assertions(1);
+      process.argv.push("--all");
+      await command.runAndCatch();
+      expect(link.all.callCount).toEqual(1);
+    });
+
+    it("should unlink all packages if --all and --unlink options are received", async () => {
+      expect.assertions(1);
+      process.argv.push("--all");
+      process.argv.push("--unlink");
+      await command.runAndCatch();
+      expect(unlink.all.callCount).toEqual(1);
+    });
+
+    it("should check links if --check option is received", async () => {
+      expect.assertions(1);
+      process.argv.push("--check");
+      await command.runAndCatch();
+      expect(check.avoidFileLinks.callCount).toEqual(1);
+    });
+  });
+});