1# CI Optimization Patterns
2 
3Strategies for efficient CI/CD with Turborepo.
4 
5## PR vs Main Branch Builds
6 
7### PR Builds: Only Affected
8 
9Test only what changed in the PR:
10 
11```yaml
12- name: Test (PR)
13  if: github.event_name == 'pull_request'
14  run: turbo run build test --affected
15```
16 
17### Main Branch: Full Build
18 
19Ensure complete validation on merge:
20 
21```yaml
22- name: Test (Main)
23  if: github.ref == 'refs/heads/main'
24  run: turbo run build test
25```
26 
27## Custom Git Ranges with --filter
28 
29For advanced scenarios, use `--filter` with git refs:
30 
31```bash
32# Changes since specific commit
33turbo run test --filter="...[abc123]"
34 
35# Changes between refs
36turbo run test --filter="...[main...HEAD]"
37 
38# Changes in last 3 commits
39turbo run test --filter="...[HEAD~3]"
40```
41 
42## Caching Strategies
43 
44### Remote Cache (Recommended)
45 
46Best performance - shared across all CI runs and developers:
47 
48```yaml
49env:
50  TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
51  TURBO_TEAM: ${{ vars.TURBO_TEAM }}
52```
53 
54### actions/cache Fallback
55 
56When remote cache isn't available:
57 
58```yaml
59- uses: actions/cache@v4
60  with:
61    path: .turbo
62    key: turbo-${{ runner.os }}-${{ github.sha }}
63    restore-keys: |
64      turbo-${{ runner.os }}-${{ github.ref }}-
65      turbo-${{ runner.os }}-
66```
67 
68Limitations:
69 
70- Cache is branch-scoped
71- PRs restore from base branch cache
72- Less efficient than remote cache
73 
74## Matrix Builds
75 
76Test across Node versions:
77 
78```yaml
79strategy:
80  matrix:
81    node: [18, 20, 22]
82 
83steps:
84  - uses: actions/setup-node@v4
85    with:
86      node-version: ${{ matrix.node }}
87 
88  - run: turbo run test
89```
90 
91## Parallelizing Across Jobs
92 
93Split tasks into separate jobs:
94 
95```yaml
96jobs:
97  lint:
98    runs-on: ubuntu-latest
99    steps:
100      - run: turbo run lint --affected
101 
102  test:
103    runs-on: ubuntu-latest
104    steps:
105      - run: turbo run test --affected
106 
107  build:
108    runs-on: ubuntu-latest
109    needs: [lint, test]
110    steps:
111      - run: turbo run build
112```
113 
114### Cache Considerations
115 
116When parallelizing:
117 
118- Each job has separate cache writes
119- Remote cache handles this automatically
120- With actions/cache, use unique keys per job to avoid conflicts
121 
122```yaml
123- uses: actions/cache@v4
124  with:
125    path: .turbo
126    key: turbo-${{ runner.os }}-${{ github.job }}-${{ github.sha }}
127```
128 
129## Conditional Tasks
130 
131Skip expensive tasks on draft PRs:
132 
133```yaml
134- name: E2E Tests
135  if: github.event.pull_request.draft == false
136  run: turbo run test:e2e --affected
137```
138 
139Or require label for full test:
140 
141```yaml
142- name: Full Test Suite
143  if: contains(github.event.pull_request.labels.*.name, 'full-test')
144  run: turbo run test
145```
146