Pull without creating a merge commit.
Update a branch only when its upstream can be fast-forwarded.
set -euo pipefail
git pull --ff-only -q
git rev-parse --abbrev-ref "@{upstream}"Expected output EXAMPLE
origin/main
Details
Requires Git and Bash. Run in a disposable practice repository. The test setup below creates the starting files and commits. The fixture adds a remote commit from a second clone; this pull integrates it. GitHub authentication is outside this local test.
Tested on Ubuntu 24.04.5 LTS · · git version 2.43.0 · git 1:2.43.0-1ubuntu7.3
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged process) / C.UTF-8
- Interpreter invocation
bash -euo pipefail -c <published code>- Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3- Code SHA-256
86612596f6cd81cc69671691a0be45226b85f63920f6ad7f3077cf6afee8644e- Dependencies
- git 1:2.43.0-1ubuntu7.3
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
git init -q -b main . git config user.name 'Example Developer' git config user.email 'developer@example.invalid' git config commit.gpgsign false printf 'first\n' > notes.txt git add notes.txt git commit -qm 'Initial notes' git init -q --bare remote.git git remote add origin ./remote.git git push -q -u origin main git clone -q -b main remote.git teammate git -C teammate config user.name 'Example Teammate' git -C teammate config user.email 'teammate@example.invalid' printf 'shared\n' >> teammate/notes.txt git -C teammate commit -qam 'Shared note' git -C teammate push -q
Observed standard output
origin/main
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.
Additional assertions that passed
Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.
assert Path('notes.txt').read_text() == 'first\nshared\n'