feat: Allow use on branch without changed js and ts file (#36)

* chore: Remove '@stryker-mutator/api' as peer dependency

* chore: Obligate use of node >= v12

* chore(package): Avoid unnecessary download of 'snyk' dependency on lib installation

* feat: Allow use on branch without changed js and ts file

If there is no altered file, stryker-diff-runner will be aborted and
will not result in a break, allowing use in the pipeline.

It will also validate if the branch passed in the '--branch' argument
exists, otherwise the execution will be aborted in error.

closes #34

* chore(index): change log to warn

* test: validate output when there is no file to be mutated

* tests: increase code coverage

* chore(package): change test script to show all tests on log

Co-authored-by: Thomas VERHOKEN <thomas.verhoken@gmail.com>

package.json

@@ -14,7 +14,7 @@
     "clean": "rm -r dist",
     "build": "npm run clean || tsc -p tsconfig.prod.json",
     "lint": "tslint --project .",
-    "test": "jest --coverage",
+    "test": "jest --coverage --silent --verbose",
     "test:ci": "npm run test && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js",
     "test:watch": "jest --watch",
     "release": "git add dist && standard-version --commit-all --releaseCommitMessageFormat=\"chore(release): %s [ci skip]\"",

src/index.ts

@@ -20,13 +20,21 @@ export default function run(commandArgs: string[]) {
   }
 
   exec(
-    `git diff origin/${branch || "master"} --name-only | grep -E -v '.*\\.test.*' | grep -e 'src/.*\\.[jt]s'`,
-    (error, stdout, stderr) => {
+    `git rev-parse --verify origin/${branch || "master"}`, (error) => {
       if (error) {
-        console.error(error.message);
-        console.error(stderr);
+        console.error(`Stryker-diff-runner:\n\t"origin/${branch || "master"}" branch was not found.\n\tStryker-diff-runner will be aborted.\n`);
         process.exit(1);
       }
+    }
+  );
+
+  exec(
+    `git diff origin/${branch || "master"} --name-only | grep -E -v '.*.test.*' | grep -e 'src/.*.[jt]s'`,
+    (error, stdout, stderr) => {
+      if (error) {
+        console.warn('Stryker-diff-runner:\n\tNo files found in the current branch to be mutated.')
+        process.exit(0);
+      }
 
       const filesToMutate = stdout.split("\n");
       filesToMutate.splice(filesToMutate.length - 1, 1);

tests/index.test.ts

@@ -26,26 +26,70 @@ describe("Stryker diff runner", () => {
     jest.restoreAllMocks();
   });
 
+  it('Should execute git rev-parse on "origin/master" by default.', () => {
+    const exitMock = jest.spyOn(process, "exit").mockImplementation();
+
+    run(["node", "exec"]);
+
+    (exec as any).mock.calls[0][1](null, "")
+
+    expect((exec as any).mock.calls[0][0]).toMatch('git rev-parse --verify origin/master');
+    expect(exitMock).not.toHaveBeenCalled();
+  });
+
+  it('Should execute git rev-parse on "origin/test" when "--branch" arg is provided.', () => {
+    run(["node", "exec", "--branch", "test"]);
+
+    expect((exec as any).mock.calls[0][0]).toMatch('git rev-parse --verify origin/test');
+  });
+
   it('Should execute git diff on "origin/master" by default.', () => {
     run(["node", "exec"]);
 
-    expect((exec as any).mock.calls[0][0]).toMatch(/^git diff origin\/master .*$/);
+    expect((exec as any).mock.calls[1][0]).toMatch(/^git diff origin\/master .*$/);
   });
 
   it('Should execute git diff on "origin/test" when "--branch" arg is provided.', () => {
     run(["node", "exec", "--branch", "test"]);
 
-    expect((exec as any).mock.calls[0][0]).toMatch(/^git diff origin\/test .*$/);
+    expect((exec as any).mock.calls[1][0]).toMatch(/^git diff origin\/test .*$/);
   });
 
-  it("Should exit when file diff command gives an error.", () => {
+  it("Should exit with branch message not found when branch 'non-existent' doesn't exist.", () => {
+    const branch = "non-existent";
     const exitMock = jest.spyOn(process, "exit").mockImplementation();
+    const consoleSpy = jest.spyOn(console, "error");
+
+    run(["node", "exec", "--branch", branch]);
+
+    (exec as any).mock.calls[0][1](new Error("NO BRANCH NON-EXISTENT"), "")
+
+    expect(exitMock).toHaveBeenCalledWith(1);
+    expect(consoleSpy).toHaveBeenCalledWith(`Stryker-diff-runner:\n\t"origin/${branch}" branch was not found.\n\tStryker-diff-runner will be aborted.\n`)
+  });
+
+  it("Should exit with branch message not found when default branch doesn't exist.", () => {
+    const exitMock = jest.spyOn(process, "exit").mockImplementation();
+    const consoleSpy = jest.spyOn(console, "error");
 
     run(["node", "exec"]);
 
-    runFileDiffCommandCallback(new Error("NOPE"), "");
+    (exec as any).mock.calls[0][1](new Error("NO BRANCH MASTER"), "")
 
     expect(exitMock).toHaveBeenCalledWith(1);
+    expect(consoleSpy).toHaveBeenCalledWith(`Stryker-diff-runner:\n\t"origin/master" branch was not found.\n\tStryker-diff-runner will be aborted.\n`)
+  });
+
+  it("should exit with a message that no files will be mutated when there is no changed file in the branch.", () => {
+    const exitMock = jest.spyOn(process, "exit").mockImplementation();
+    const consoleSpy = jest.spyOn(console, "warn");
+
+    run(["node", "exec"]);
+
+    runFileDiffCommandCallback(new Error("NO FILE"), "");
+
+    expect(exitMock).toHaveBeenCalledWith(0);
+    expect(consoleSpy).toHaveBeenCalledWith('Stryker-diff-runner:\n\tNo files found in the current branch to be mutated.')
   });
 
   it("Should run mutation test with default loaded configuration when no args are provided to the run.", (done) => {
@@ -234,6 +278,6 @@ describe("Stryker diff runner", () => {
   }
 
   function runFileDiffCommandCallback(error: Error | null, fileDiffList: string) {
-    (exec as any).mock.calls[0][1](error, fileDiffList);
+    (exec as any).mock.calls[1][1](error, fileDiffList);
   }
 });