CI/CD pipeline setup in Deno - Step-by-Step Execution

Concept Flow - CI/CD pipeline setup

Code Commit

↓

Trigger Pipeline

↓

Run Tests

↓

Build

↓

Deploy

↓

Notify Success

This flow shows how code commits trigger the pipeline, run tests, build, deploy, and notify based on results.

Execution Sample

Deno

steps:
  - name: Run Tests
    run: deno test
  - name: Build
    run: deno bundle main.ts bundle.js
  - name: Deploy
    run: ./deploy.sh

This pipeline runs tests, builds a bundle, and deploys the app automatically.

Execution Table

Step	Action	Command Run	Result	Next Step
1	Trigger pipeline on commit	N/A	Pipeline started	Run Tests
2	Run Tests	deno test	All tests passed	Build
3	Build	deno bundle main.ts bundle.js	Bundle created	Deploy
4	Deploy	./deploy.sh	Deployment successful	Notify Success
5	Notify Success	N/A	Team notified of success	End

💡 Pipeline ends after notifying success or failure.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
pipeline_status	not started	tests passed	build done	deployed	success notified
test_result	none	pass	pass	pass	pass
build_artifact	none	none	bundle.js created	bundle.js deployed	bundle.js deployed

Key Moments - 2 Insights

Why does the pipeline stop if tests fail?

Because the execution_table shows the next step after tests only happens if tests pass. If tests fail, the pipeline triggers a notification and stops to avoid deploying broken code.

What happens if the build step fails?

The pipeline does not proceed to deploy. The execution_table shows deployment only after a successful build, so failure here stops the pipeline and triggers failure notification.

Visual Quiz - 3 Questions

Look at the execution table, what is the pipeline_status after Step 3?

A deployed

B tests passed

C build done

D success notified

💡 Hint

Check variable_tracker row for pipeline_status after Step 3.

At which step does the pipeline notify the team of success?

A Step 2

B Step 5

C Step 3

D Step 4

💡 Hint

See execution_table row with Notify Success action.

If tests fail at Step 2, what is the next step according to the flow?

A Notify Dev

B Build

C Deploy

D Notify Success

💡 Hint

Refer to concept_flow where test failure leads to Notify Dev.

Concept Snapshot

CI/CD pipeline setup:
- Triggered by code commit
- Runs tests first (deno test)
- Builds bundle if tests pass (deno bundle)
- Deploys app if build succeeds
- Notifies team on success or failure
- Stops pipeline on test or build failure

Full Transcript

A CI/CD pipeline starts when code is committed. It runs tests using 'deno test'. If tests pass, it builds the app bundle with 'deno bundle'. After a successful build, it deploys the app using a deploy script. Finally, it notifies the team of success. If tests or build fail, the pipeline stops and notifies the developers to fix issues before continuing.

Practice

1. What is the main purpose of setting up a CI/CD pipeline for a Deno project?

easy

A. To automate testing and deployment processes

B. To write code faster manually

C. To increase the size of the project files

D. To disable automatic updates

Solution

1. Step 1: Understand CI/CD pipeline purpose

   A CI/CD pipeline automates repetitive tasks like testing and deployment to save time and reduce errors.

2. Step 2: Match purpose to options

   Only To automate testing and deployment processes describes automation of testing and deployment, which is the main goal.

3. Final Answer:

   To automate testing and deployment processes -> Option A

4. Quick Check:

   CI/CD automates testing and deployment = A [OK]

Hint: CI/CD means automating build, test, and deploy steps [OK]

Common Mistakes:

• Thinking CI/CD is about writing code manually
• Confusing CI/CD with increasing file size
• Believing CI/CD disables updates

2. Which of the following is the correct command to run tests in a Deno CI/CD pipeline?

easy

A. deno test

B. deno run test

C. deno build test

D. deno deploy test

Solution

1. Step 1: Recall Deno test command

   The official command to run tests in Deno is deno test.

2. Step 2: Compare options with correct syntax

   Only deno test matches the correct command syntax for running tests.

3. Final Answer:

   deno test -> Option A

4. Quick Check:

   Run tests with 'deno test' = A [OK]

Hint: Use 'deno test' to run tests, not 'deno run test' [OK]

Common Mistakes:

• Using 'deno run test' which runs a script, not tests
• Confusing build or deploy commands with test command
• Adding extra words like 'build' or 'deploy' incorrectly

3. Given this CI step in a Deno pipeline:

steps:
  - name: Run tests
    run: deno test --unstable
  - name: Bundle code
    run: deno bundle mod.ts bundle.js

What will be the result if tests fail?

medium

A. The pipeline skips tests and bundles code

B. The pipeline stops and does not bundle the code

C. The pipeline continues and bundles the code anyway

D. The pipeline deletes the bundle.js file

Solution

1. Step 1: Understand default pipeline behavior on failure

   In most CI/CD systems, if a test step fails, the pipeline stops to prevent deploying broken code.

2. Step 2: Apply to given steps

   If deno test --unstable fails, the next step to bundle code will not run.

3. Final Answer:

   The pipeline stops and does not bundle the code -> Option B

4. Quick Check:

   Failed tests stop pipeline = C [OK]

Hint: Failed tests usually stop pipeline to avoid bad deploys [OK]

Common Mistakes:

• Assuming pipeline continues after test failure
• Thinking tests are skipped automatically
• Believing files get deleted on test failure

4. You wrote this pipeline step:

steps:
  - name: Bundle code
    run: deno bundle mod.ts -o bundle.js

But the pipeline fails with an error. What is the likely cause?

medium

A. The pipeline requires 'deno test' before bundling

B. The file 'mod.ts' does not exist

C. The 'run' keyword is misspelled

D. The '-o' flag is not valid for 'deno bundle'

Solution

1. Step 1: Check 'deno bundle' syntax

   The correct syntax to specify output file is: deno bundle input.ts output.js without '-o' flag.

2. Step 2: Identify error cause

   Using '-o' causes an error because 'deno bundle' does not support it.

3. Final Answer:

   The '-o' flag is not valid for 'deno bundle' -> Option D

4. Quick Check:

   Output file is positional, no '-o' flag = D [OK]

Hint: Use positional output filename, not '-o', with deno bundle [OK]

Common Mistakes:

• Adding '-o' flag like other bundlers
• Assuming file existence without checking
• Thinking 'run' keyword is wrong
• Believing tests must run before bundling always

5. You want to create a CI/CD pipeline that runs tests, bundles code, and then deploys only if tests pass. Which YAML snippet correctly represents this sequence?

hard

A. steps:
- run: deno bundle mod.ts bundle.js
- run: deno test
- run: deploy.sh

B. steps:
- run: deploy.sh
- run: deno test
- run: deno bundle mod.ts bundle.js

C. steps:
- run: deno test
- run: deno bundle mod.ts bundle.js
- run: deploy.sh

D. steps:
- run: deno test
- run: deploy.sh
- run: deno bundle mod.ts bundle.js

Solution

1. Step 1: Determine correct order for CI/CD steps

   Tests must run first to verify code, then bundle code, then deploy if tests pass.

2. Step 2: Match order with options

   Only steps: - run: deno test - run: deno bundle mod.ts bundle.js - run: deploy.sh runs tests first, then bundles, then deploys.

3. Final Answer:

   Tests first, then bundle, then deploy -> Option C

4. Quick Check:

   Test -> Bundle -> Deploy = B [OK]

Hint: Test first, then bundle, then deploy in pipeline steps [OK]

Common Mistakes:

• Deploying before tests run
• Bundling before tests
• Changing step order incorrectly