GH-200 Practice Test

Sample GH-200 Practice Questions

10 real questions from the free GH-200bank. Pick an answer in your head, then open “Show answer” for the explanation.

1. 1. A step needs to mask a dynamically generated value (not stored as a repository secret) so it never appears in plaintext in the workflow logs from that point forward. Which workflow command accomplishes this?

   • A. echo "::add-mask::$VALUE"
   • B. echo "::stop-commands::$VALUE"
   • C. echo "::set-secret::$VALUE"
   • D. echo "::hide::$VALUE"
   Show answer

   Correct answer: A

   The add-mask workflow command registers a runtime value for masking, causing GitHub Actions to replace any future occurrence of that exact string in the log output with ***, even though it was never stored as a configured secret. stop-commands is used to pause command processing for a block of log output, and set-secret and hide are not valid GitHub Actions workflow commands.

2. 2. A calling workflow needs to pass a string value into a reusable workflow invoked with uses: org/repo/.github/workflows/build.yml@v1. Where should that value be declared?

   • A. As a repository variable, since reusable workflows cannot receive inputs directly
   • B. Under a with: block on the job that calls the reusable workflow, matching an inputs: entry the reusable workflow declares under on: workflow_call
   • C. Inside the env: block of the calling job, since workflow_call automatically maps env vars to inputs
   • D. In the secrets: block, since data passed to reusable workflows must be treated as sensitive
   Show answer

   Correct answer: B

   Reusable workflows declare accepted parameters under on: workflow_call: inputs:, and the calling job supplies matching values in a with: block, the same pattern used for actions. Reusable workflows do support direct inputs, plain env vars are not auto-mapped to workflow_call inputs, and non-sensitive values do not need to go through secrets:.

3. 3. A step needs to pass a computed version string to later steps in the same job. Which mechanism is the current recommended approach?

   • A. Use the deprecated ::set-output name=version::1.2.3 workflow command, which remains the primary recommended method
   • B. Write the value to a file named output.txt in the workspace and hope later steps read it by convention
   • C. Print the value to stdout; GitHub automatically parses stdout for key=value pairs
   • D. Write echo "version=1.2.3" >> "$GITHUB_OUTPUT" in the step and reference it as ${{ steps.<id>.outputs.version }}
   Show answer

   Correct answer: D

   Writing key=value pairs to the file referenced by the GITHUB_OUTPUT environment variable is the current supported way to set step outputs, consumed as steps.<step-id>.outputs.<name>. The ::set-output:: workflow command is deprecated, writing to an arbitrary file has no built-in consumption mechanism, and GitHub does not parse arbitrary stdout for key=value pairs.

4. 4. A step needs to set a multi-line string as a step output (for example, a formatted changelog) using GITHUB_OUTPUT. Using a single echo "name=value" >> "$GITHUB_OUTPUT" line will not work correctly for multi-line content. Which syntax correctly handles this?

   • A. Escape each newline character with a backslash before writing to GITHUB_OUTPUT
   • B. Base64-encode the value and let GitHub Actions automatically decode GITHUB_OUTPUT entries
   • C. Use a heredoc-style delimiter: write name<<EOF to GITHUB_OUTPUT, then the multi-line content, then a closing line containing just EOF
   • D. Write each line as a separate GITHUB_OUTPUT entry using the same output name repeated
   Show answer

   Correct answer: C

   For multi-line values, GitHub Actions requires a delimiter-based (heredoc) syntax - writing name<<DELIMITER, then the raw multi-line content, then a closing line containing just DELIMITER - to the GITHUB_OUTPUT file, which correctly captures embedded newlines as a single output value. Escaping newlines manually is unsupported and error-prone, GitHub Actions does not auto-decode base64 content in GITHUB_OUTPUT, and repeating the same output name across multiple lines simply overwrites the value rather than concatenating it.

5. 5. Which workflow command is used inside a step to add a line of text to the run's visible job summary, rendered as Markdown on the run page?

   • A. Use ::notice:: with a summary flag
   • B. Write to $GITHUB_ENV
   • C. Write to the file referenced by $GITHUB_STEP_SUMMARY
   • D. Use ::debug:: prefixed with summary=true
   Show answer

   Correct answer: C

   Appending Markdown content to the file path in the GITHUB_STEP_SUMMARY environment variable renders that content as a per-step (and aggregated per-job) summary on the workflow run page. ::notice:: creates an annotation, not a summary section, GITHUB_ENV sets environment variables for later steps, and ::debug:: only affects debug logging visibility.