fix(content-docs): suppress git error on multiple occurrences (#6973)

jest/utils/git.ts

@@ -0,0 +1,63 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import fs from 'fs-extra';
+import os from 'os';
+import path from 'path';
+import shell from 'shelljs';
+
+class Git {
+  constructor(private dir: string) {
+    const res = shell.exec('git init', {cwd: dir, silent: true});
+    if (res.code !== 0) {
+      throw new Error(`git init exited with code ${res.code}.
+stderr: ${res.stderr}
+stdout: ${res.stdout}`);
+    }
+    // Doesn't matter currently
+    shell.exec('git config user.email "test@jc-verse.com"', {
+      cwd: dir,
+      silent: true,
+    });
+    shell.exec('git config user.name "Test"', {cwd: dir, silent: true});
+
+    shell.exec('git commit --allow-empty -m "First commit"', {
+      cwd: dir,
+      silent: true,
+    });
+  }
+  commit(msg: string, date: string, author: string): void {
+    const addRes = shell.exec('git add .', {cwd: this.dir, silent: true});
+    const commitRes = shell.exec(
+      `git commit -m "${msg}" --date "${date}T00:00:00Z" --author "${author}"`,
+      {
+        cwd: this.dir,
+        env: {GIT_COMMITTER_DATE: `${date}T00:00:00Z`},
+        silent: true,
+      },
+    );
+    if (addRes.code !== 0) {
+      throw new Error(`git add exited with code ${addRes.code}.
+stderr: ${addRes.stderr}
+stdout: ${addRes.stdout}`);
+    }
+    if (commitRes.code !== 0) {
+      throw new Error(`git commit exited with code ${commitRes.code}.
+stderr: ${commitRes.stderr}
+stdout: ${commitRes.stdout}`);
+    }
+  }
+}
+
+// This function is sync so the same mock repo can be shared across tests
+export function createTempRepo(): {repoDir: string; git: Git} {
+  const repoDir = fs.mkdtempSync(path.join(os.tmpdir(), 'git-test-repo'));
+
+  const git = new Git(repoDir);
+
+  return {repoDir, git};
+}