feat(developer): use git's last commit date for keyboard_info

Author: mcdurdin

developer/src/kmc-keyboard-info/src/index.ts

@@ -51,6 +51,9 @@ export interface KeyboardInfoSources {
 
   /** The source package filename and relative path (.kps) */
   kpsFilename: string;
+
+  /** Last modification date for files in the project folder 'YYYY-MM-DDThh:mm:ssZ' */
+  lastCommitDate: string;
 };
 
 export class KeyboardInfoCompiler {
@@ -164,8 +167,8 @@ export class KeyboardInfoCompiler {
 
     this.fillLanguages(keyboard_info, kmpJsonData);
 
-    // TODO: use: TZ=UTC0 git log -1 --no-merges --date=format:%Y-%m-%dT%H:%M:%SZ --format=%ad
-    keyboard_info.lastModifiedDate = (new Date).toISOString();
+    // If a last commit date is not given, then just use the current time
+    keyboard_info.lastModifiedDate = sources.lastCommitDate ?? (new Date).toISOString();
 
     keyboard_info.packageFilename = this.callbacks.path.basename(sources.kmpFilename);
 

developer/src/kmc/src/commands/buildClasses/BuildKeyboardInfo.ts

@@ -5,6 +5,7 @@ import { KeyboardInfoCompiler } from '@keymanapp/kmc-keyboard-info';
 import { loadProject } from '../../util/projectLoader.js';
 import { InfrastructureMessages } from '../../messages/infrastructureMessages.js';
 import { calculateSourcePath } from '../../util/calculateSourcePath.js';
+import { getLastGitCommitDate } from '../../util/getLastGitCommitDate.js';
 
 export class BuildKeyboardInfo extends BuildActivity {
   public get name(): string { return 'Keyboard metadata'; }
@@ -43,13 +44,15 @@ export class BuildKeyboardInfo extends BuildActivity {
 
 
     const jsFilename = project.resolveOutputFilePath(keyboard, KeymanFileTypes.Source.KeymanKeyboard, KeymanFileTypes.Binary.WebKeyboard);
+    const lastCommitDate = getLastGitCommitDate(callbacks.path.dirname(project.resolveInputFilePath(metadata)));
 
     const compiler = new KeyboardInfoCompiler(callbacks);
     const data = compiler.writeMergedKeyboardInfoFile({
       kmpFilename:  project.resolveOutputFilePath(kps, KeymanFileTypes.Source.Package, KeymanFileTypes.Binary.Package),
       kpsFilename: project.resolveInputFilePath(kps),
       jsFilename: fs.existsSync(jsFilename) ? jsFilename : undefined,
-      sourcePath: calculateSourcePath(infile)
+      sourcePath: calculateSourcePath(infile),
+      lastCommitDate
     });
 
     if(data == null) {

developer/src/kmc/src/util/getLastGitCommitDate.ts

@@ -0,0 +1,45 @@
+import { execFileSync } from 'child_process';
+
+/**
+ * Returns the date and time of the last commit from git for the passed in path
+ * @param path   Path for which to retrieve the last commit message
+ * @returns string, in RFC3339, 'YYYY-MM-DDThh:nn:ssZ'
+ */
+export function getLastGitCommitDate(path: string): string {
+  // TZ=UTC0 git log -1 --no-merges --date=format:%Y-%m-%dT%H:%M:%SZ --format=%ad
+  let result = null;
+
+  try {
+    result = execFileSync('git', [
+      'log',                                // git log
+      '-1',                                 // one commit only
+      '--no-merges',                        // we're only interested in 'real' commits
+      '--date=format:%Y-%m-%dT%H:%M:%SZ',   // format the date in our expected RFC3339 format
+      '--format=%ad'                        // emit only the commit date
+    ], {
+      env: { ...process.env, TZ: 'TZ0' },   // use UTC timezone, not local
+      encoding: 'utf-8',                    // force a string result rather than Buffer
+      windowsHide: true,                    // on windows, we may need this to suppress a console window popup
+      cwd: path,                            // path to run git from
+      stdio: ['pipe', 'pipe', 'pipe']       // all output via pipe, so we don't get git errors on console
+    });
+  } catch (e) {
+    // If git is not available, or the file is not in-repo, then it is probably
+    // fine to just silently return null, as the only machines where this is
+    // critical are the CI machines where we build and deploy .keyboard_info
+    // files, and where git will always be available. It would be possible to
+    // have this raise an error in CI environments, but the chance of error
+    // seems low.
+    return null;
+  }
+
+  result = result.trim();
+
+  // We'll only return the result if it walks like a date, swims like a date,
+  // and quacks like a date.
+  if (!result.match(/^\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\dZ$/)) {
+    return null;
+  }
+
+  return result;
+}

developer/src/kmc/test/test-getLastGitCommitDate.ts

@@ -0,0 +1,17 @@
+import { assert } from 'chai';
+import 'mocha';
+import { makePathToFixture } from './helpers/index.js';
+import { getLastGitCommitDate } from '../src/util/getLastGitCommitDate.js';
+
+describe('getLastGitCommitDate', function () {
+  it('should return a valid date for a folder in this repo', async function() {
+    const path = makePathToFixture('.');
+    const date = getLastGitCommitDate(path);
+    assert.match(date, /^\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\dZ$/);
+  });
+
+  it('should return null for a folder outside the repo', async function() {
+    const date = getLastGitCommitDate('/');
+    assert.isNull(date);
+  });
+});