Working with GitHub Repositories: free practice questions

'git revert <commit-sha>' creates a new commit that applies the inverse of the specified commit's changes, effectively undoing its effect while preserving the entire existing history — safe to use on shared branches. 'git reset --hard' moves the branch pointer to an earlier state, which rewrites history and would cause problems for other developers who have already based work on the removed commits. 'git commit --amend' can only modify the most recent commit, not an arbitrary earlier one. 'git rebase -i' (interactive rebase) also rewrites history by removing commits, which is dangerous on shared branches and would require force-pushing.

A dev container configuration — typically a devcontainer.json file located in the .devcontainer directory — tells GitHub Codespaces (and other compatible tools) exactly what Docker image to use, which VS Code extensions to install, which ports to forward, and which setup commands to run when creating the environment. This ensures every developer gets an identical, reproducible environment automatically. Option A is incorrect because GitHub Actions workflows run in response to repository events (like pushes or pull requests) and are not used to configure the Codespaces environment itself. Option C is incorrect because dependency manifest files (requirements.txt, package.json) describe project dependencies but do not configure the OS-level environment, editor extensions, or runtime versions in Codespaces. Option D is incorrect because CONTRIBUTING.md is a documentation file for human readers; it has no effect on the automated provisioning of a Codespace.

When a user closes a Codespace browser tab without stopping it, the Codespace enters a suspended (dormant) state after a short inactivity timeout. The container and its filesystem — including uncommitted changes — are preserved in that suspended state until the user resumes or the Codespace reaches the configured retention period and is deleted. It is NOT immediately deleted; work is preserved in the suspended state. GitHub never auto-commits or auto-pushes uncommitted changes on the user's behalf. The Codespace does not continue running indefinitely; it suspends after the inactivity timeout (default 30 minutes) to avoid unnecessary compute charges.

git commit --amend allows the developer to modify the most recent (unpushed) commit — including its message and its staged content. By removing the credentials from the files, staging the corrected files with 'git add', and then running 'git commit --amend', the developer replaces the last commit with a new, corrected one. Option A (git revert HEAD) is incorrect because it creates a brand-new commit that undoes the previous one, which would still expose the credentials in the history. Option B (git reset HEAD~1) undoes the commit and unstages its changes but does not fix the commit — it leaves the developer with uncommitted changes that still need to be cleaned up; it also doesn't let them directly amend the message. Option D (git cherry-pick HEAD) is used to apply a commit from one branch onto another and is irrelevant here.

The Traffic insights page shows: (1) clone counts — how many times the repository has been cloned over the past 14 days — and (2) visitor/view counts — unique visitors and total page views over the same period. It also shows referring sites and popular content, but the question asks to select two. Contributor names and emails are found in the 'Contributors' insights page, not Traffic. Pull request lists are found in the Pull Requests tab, not Insights → Traffic.