Merge pull request #28 from s0/skip-empty-commits

Allow skipping of empty commits

README.md

@@ -168,6 +168,7 @@ All configuration options are passed in via `env`, as environment variables.
 | `KNOWN_HOSTS_FILE` | Path to a file in the repository that contains the known SSH fingerprints for the target host. | When the target host is not github.com |
 | `GITHUB_TOKEN`     | Should always be equal to `${{ secrets.GITHUB_TOKEN }}` | When `REPO = self` |
 | `SQUASH_HISTORY`   | If set to `true`, all previous commits on the target branch will be discarded. For example, if you are deploying a static site with lots of binary artifacts, this can help the repository becoming overly bloated. | No |
+| `SKIP_EMPTY_COMMITS` | If set to `true`, commits will only be pushed if the contents of the target branch will be changed as a result. This is useful if, for example, you'd like to easily track which upstream changes result in changes to your target branch. | No |
 | `MESSAGE`          | A custom template to use as the commit message pushed to the target branch. See [custom commit messages](#custom-commit-messages). | No |
 | `TAG` | A string following the [git-check-ref-format](https://git-scm.com/docs/git-check-ref-format) that tags the commit with a lightweight git-tag. | No |
 

action/dist/index.js

@@ -8016,6 +8016,7 @@ var config = (function () {
     var branch = ENV.BRANCH;
     var folder = ENV.FOLDER;
     var squashHistory = ENV.SQUASH_HISTORY === 'true';
+    var skipEmptyCommits = ENV.SKIP_EMPTY_COMMITS === 'true';
     var message = ENV.MESSAGE || DEFAULT_MESSAGE;
     var tag = ENV.TAG;
     // Determine the type of URL
@@ -8030,6 +8031,7 @@ var config = (function () {
             branch: branch,
             folder: folder,
             squashHistory: squashHistory,
+            skipEmptyCommits: skipEmptyCommits,
             mode: 'self',
             message: message,
             tag: tag,
@@ -8045,6 +8047,7 @@ var config = (function () {
             branch: branch,
             folder: folder,
             squashHistory: squashHistory,
+            skipEmptyCommits: skipEmptyCommits,
             mode: 'ssh',
             parsedUrl: parsedUrl,
             privateKey: ENV.SSH_PRIVATE_KEY,
@@ -8085,7 +8088,7 @@ var writeToProcess = function (command, args, opts) { return new Promise(functio
     });
 }); };
 (function () { return __awaiter(void 0, void 0, void 0, function () {
-    var TMP_PATH, REPO_TEMP, SSH_AUTH_SOCK, event, _a, _b, name, email, tag, getGitInformation, gitInfo, env, known_hosts, sshAgentMatch, _c, _d, branchCheck, folder, message, forceArg, tagsArg, push;
+    var TMP_PATH, REPO_TEMP, SSH_AUTH_SOCK, event, _a, _b, name, email, tag, getGitInformation, gitInfo, env, known_hosts, sshAgentMatch, _c, _d, branchCheck, folder, message, head, currentCommit, previousCommit, forceArg, tagsArg, push;
     var _e, _f;
     return __generator(this, function (_g) {
         switch (_g.label) {
@@ -8313,21 +8316,51 @@ var writeToProcess = function (command, args, opts) { return new Promise(functio
                 _g.sent();
                 _g.label = 30;
             case 30:
+                if (!config.skipEmptyCommits) return [3 /*break*/, 34];
+                console.log("##[info] Checking whether contents have changed before pushing");
+                return [4 /*yield*/, isomorphic_git_1.default.resolveRef({
+                        fs: fs,
+                        dir: REPO_TEMP,
+                        ref: 'HEAD'
+                    })];
+            case 31:
+                head = _g.sent();
+                return [4 /*yield*/, isomorphic_git_1.default.readCommit({
+                        fs: fs,
+                        dir: REPO_TEMP,
+                        oid: head,
+                    })];
+            case 32:
+                currentCommit = _g.sent();
+                if (!(currentCommit.commit.parent.length === 1)) return [3 /*break*/, 34];
+                return [4 /*yield*/, isomorphic_git_1.default.readCommit({
+                        fs: fs,
+                        dir: REPO_TEMP,
+                        oid: currentCommit.commit.parent[0],
+                    })];
+            case 33:
+                previousCommit = _g.sent();
+                if (currentCommit.commit.tree === previousCommit.commit.tree) {
+                    console.log("##[info] Contents of target repo unchanged, exiting.");
+                    return [2 /*return*/];
+                }
+                _g.label = 34;
+            case 34:
                 console.log("##[info] Pushing");
                 forceArg = config.squashHistory ? '-f' : '';
                 tagsArg = tag ? '--tags' : '';
                 return [4 /*yield*/, exec("git push " + forceArg + " origin \"" + config.branch + "\" " + tagsArg, { env: env, cwd: REPO_TEMP })];
-            case 31:
+            case 35:
                 push = _g.sent();
                 console.log(push.stdout);
                 console.log("##[info] Deployment Successful");
-                if (!(config.mode === 'ssh')) return [3 /*break*/, 33];
+                if (!(config.mode === 'ssh')) return [3 /*break*/, 37];
                 console.log("##[info] Killing ssh-agent");
                 return [4 /*yield*/, exec("ssh-agent -k", { env: env })];
-            case 32:
+            case 36:
                 _g.sent();
-                _g.label = 33;
-            case 33: return [2 /*return*/];
+                _g.label = 37;
+            case 37: return [2 /*return*/];
         }
     });
 }); })().catch(function (err) {

action/src/index.ts

@@ -45,6 +45,13 @@ export interface EnvironmentVariables {
    * Set to "true" to clear all of the history of the target branch and force push
    */
   SQUASH_HISTORY?: string;
+  /**
+   * Set to "true" to avoid pushing commits that don't change any files.
+   * 
+   * This is useful for example when you want to be able to easily identify
+   * which upstream changes resulted in changes to this repository.
+   */
+  SKIP_EMPTY_COMMITS?: string;
   /**
    * An optional template string to use for the commit message,
    * if not provided, a default template is used.
@@ -119,6 +126,7 @@ interface BaseConfig {
   folder: string;
   repo: string;
   squashHistory: boolean;
+  skipEmptyCommits: boolean;
   message: string;
   tag?: string;
 }
@@ -158,6 +166,7 @@ const config: Config = (() => {
   const branch = ENV.BRANCH;
   const folder = ENV.FOLDER;
   const squashHistory = ENV.SQUASH_HISTORY === 'true';
+  const skipEmptyCommits = ENV.SKIP_EMPTY_COMMITS === 'true';
   const message = ENV.MESSAGE || DEFAULT_MESSAGE;
   const tag = ENV.TAG;
 
@@ -173,6 +182,7 @@ const config: Config = (() => {
       branch,
       folder,
       squashHistory,
+      skipEmptyCommits,
       mode: 'self',
       message,
       tag,
@@ -189,6 +199,7 @@ const config: Config = (() => {
       branch,
       folder,
       squashHistory,
+      skipEmptyCommits,
       mode: 'ssh',
       parsedUrl,
       privateKey: ENV.SSH_PRIVATE_KEY,
@@ -415,6 +426,32 @@ const writeToProcess = (command: string, args: string[], opts: { env: { [id: str
       ref: tag,
     });
   }
+  if (config.skipEmptyCommits) {
+    console.log(`##[info] Checking whether contents have changed before pushing`);
+    // Before we push, check whether it changed the tree,
+    // and avoid pushing if not
+    const head = await git.resolveRef({
+      fs,
+      dir: REPO_TEMP,
+      ref: 'HEAD'
+    });
+    const currentCommit = await git.readCommit({
+      fs,
+      dir: REPO_TEMP,
+      oid: head,
+    });
+    if (currentCommit.commit.parent.length === 1) {
+      const previousCommit = await git.readCommit({
+        fs,
+        dir: REPO_TEMP,
+        oid: currentCommit.commit.parent[0],
+      });
+      if (currentCommit.commit.tree === previousCommit.commit.tree) {
+        console.log(`##[info] Contents of target repo unchanged, exiting.`);
+        return;
+      }
+    }
+  }
   console.log(`##[info] Pushing`);
   const forceArg = config.squashHistory ? '-f' : '';
   const tagsArg = tag ? '--tags' : '';

action/test/jest-global-setup-hooks.ts

@@ -1 +1 @@
-jest.setTimeout(15000);
+jest.setTimeout(1000 * 60 * 60);

action/test/specs/__snapshots__/ssh-skip-empty-commits.spec.ts.snap

@@ -0,0 +1,12 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Skip empty commits 1`] = `
+"msg:Update branch-a to output generated at <sha1>
+
+tree:b60735c9b4d9728b47c0f2752bb973cd6f3d9d80
+author:s0 <[email protected]>
+msg:Update branch-a to output generated at <sha2>
+
+tree:8bf87c66655949e66937b11593cc4ae732d1f610
+author:s0 <[email protected]>"
+`;

action/test/specs/ssh-github.spec.ts

@@ -7,8 +7,6 @@ const DATA_DIR = path.join(util.DATA_DIR, 'ssh-no-branch-github');
 
 it('Deploy to an existing branch on GitHub', async () => {
 
-  jest.setTimeout(1000 * 60 * 60);
-
   // Create empty repo
   await util.mkdir(REPO_DIR);
   await util.execWithOutput('git init --bare', { cwd: REPO_DIR });

action/test/specs/ssh-skip-empty-commits.spec.ts

@@ -0,0 +1,82 @@
+import * as path from 'path';
+
+import * as util from '../util';
+
+const REPO_DIR = path.join(util.REPOS_DIR, 'ssh-skip-empty-commits.git');
+const DATA_DIR = path.join(util.DATA_DIR, 'ssh-skip-empty-commits');
+
+it('Skip empty commits', async () => {
+
+  // Create empty repo
+  await util.mkdir(REPO_DIR);
+  await util.execWithOutput('git init --bare', { cwd: REPO_DIR });
+
+  // Create dummy data
+  await util.mkdir(DATA_DIR);
+  await util.mkdir(path.join(DATA_DIR, 'dummy'));
+  await util.writeFile(path.join(DATA_DIR, 'dummy', 'baz'), 'foobar');
+  await util.writeFile(path.join(DATA_DIR, 'dummy', '.bat'), 'foobar');
+
+  // Run Action
+  await util.runWithGithubEnv(
+    path.basename(__filename),
+    {
+      REPO: 'ssh://git@git-ssh/git-server/repos/ssh-skip-empty-commits.git',
+      BRANCH: 'branch-a',
+      FOLDER: DATA_DIR,
+      SSH_PRIVATE_KEY: (await util.readFile(util.SSH_PRIVATE_KEY)).toString(),
+      KNOWN_HOSTS_FILE: util.KNOWN_HOSTS,
+      SKIP_EMPTY_COMMITS: 'true',
+    },
+    's0/test',
+    {},
+    's0',
+  );
+  const fullSha1 = await util.getFullRepoSha();
+  // Change files and run action again
+  await util.writeFile(path.join(DATA_DIR, 'dummy', 'bat'), 'foobar');
+  await util.runWithGithubEnv(
+    path.basename(__filename),
+    {
+      REPO: 'ssh://git@git-ssh/git-server/repos/ssh-skip-empty-commits.git',
+      BRANCH: 'branch-a',
+      FOLDER: DATA_DIR,
+      SSH_PRIVATE_KEY: (await util.readFile(util.SSH_PRIVATE_KEY)).toString(),
+      KNOWN_HOSTS_FILE: util.KNOWN_HOSTS,
+      SKIP_EMPTY_COMMITS: 'true',
+    },
+    's0/test',
+    {},
+    's0',
+  );
+  const fullSha2 = await util.getFullRepoSha();
+  // Run the action again with no content changes to test skip behaviour
+  await util.runWithGithubEnv(
+    path.basename(__filename),
+    {
+      REPO: 'ssh://git@git-ssh/git-server/repos/ssh-skip-empty-commits.git',
+      BRANCH: 'branch-a',
+      FOLDER: DATA_DIR,
+      SSH_PRIVATE_KEY: (await util.readFile(util.SSH_PRIVATE_KEY)).toString(),
+      KNOWN_HOSTS_FILE: util.KNOWN_HOSTS,
+      SKIP_EMPTY_COMMITS: 'true',
+    },
+    's0/test',
+    {},
+    's0',
+  );
+
+  // Check that the log of the repo is as expected
+  // (check tree-hash, commit message, and author)
+  // TODO: test {msg} placeholder and running action outside of a git repo
+  let log = (await util.exec(
+    'git log --pretty="format:msg:%B%ntree:%T%nauthor:%an <%ae>" branch-a',
+    {
+      cwd: REPO_DIR
+    }
+  )).stdout;
+  const sha1 = fullSha1.substr(0, 7);
+  const sha2 = fullSha2.substr(0, 7);
+  const cleanedLog = log.replace(sha1, '<sha1>').replace(sha2, '<sha2>');
+  expect(cleanedLog).toMatchSnapshot();
+});