wip

.github/workflows/fuzz.yml

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+name: Fuzz test
+on:
+  pull_request:
+jobs:
+  find-tests:
+    name: Find fuzz tests
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Find fuzz tests
+        id: set-matrix
+        run: |
+          TEST_FILES=$(find . -name '*_test.go' -not -path './vendor/*')
+
+          RESULTS=()
+
+          for FILE in $TEST_FILES; do
+            FUZZ_FUNC=$(grep -E 'func Fuzz\w*' $FILE | sed 's/func //' | sed 's/(.*$//')
+            if [ -z "$FUZZ_FUNC" ]; then
+              continue
+            fi
+
+            PACKAGE_PATH=$(dirname ${FILE#./})
+            RESULTS+=("{\"package\":\"$PACKAGE_PATH\",\"function\":\"$FUZZ_FUNC\"}")
+
+            echo "Found $PACKAGE_PATH :: $FUZZ_FUNC"
+          done
+
+          NUM_RESULTS=${#RESULTS[@]}
+          INCLUDE_STRING=""
+          for (( i=0; i<$NUM_RESULTS; i++ )); do
+            INCLUDE_STRING+="${RESULTS[$i]}"
+
+            if [[ $i -lt $(($NUM_RESULTS-1)) ]]; then
+              INCLUDE_STRING+=","
+            fi
+          done
+
+          echo 'matrix={"include": ['$INCLUDE_STRING']}' >> $GITHUB_OUTPUT
+
+  fuzz:
+    name: "${{ matrix.package }} :: ${{ matrix.function }}"
+    runs-on: ubuntu-latest
+    if: needs.find-tests.outputs.matrix != ''
+    needs: [find-tests]
+    strategy:
+      fail-fast: false # Allow other jobs in the matrix to run even if a single one fails.
+      matrix: ${{fromJson(needs.find-tests.outputs.matrix)}}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go 1.22
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+          cache: false
+
+      - name: Find cache location
+        run:
+          echo "FUZZ_CACHE=$(go env GOCACHE)/fuzz" >> $GITHUB_ENV
+
+      - name: Restore corpus
+        uses: actions/cache@v4
+        with:
+          path: ${{ env.FUZZ_CACHE }}
+          key: fuzz-${{ matrix.package }}-${{ matrix.function }}-${{ github.sha }}
+          restore-keys: |
+            fuzz-${{ matrix.package }}-${{ matrix.function }}-
+          save-always: true
+
+      - name: Fuzz
+        run: |
+          cd "${{ matrix.package }}"
+          go test -fuzz="${{ matrix.function }}\$" -run="${{ matrix.function }}\$" -fuzztime=5s .
+
+      # Fuzzing may have failed because of an existing bug, or it may have
+      # found a new one and written a new corpus entry in testdata/ relative to
+      # the package.
+      #
+      # If that file was written, we should save it as an artifact and then
+      # create an issue.
+
+      - name: Check for new corpus entry
+        id: new-entry
+        if: ${{ failure() }}
+        run: |
+          UNTRACKED=$(git ls-files . --exclude-standard --others)
+          if [ -z "$UNTRACKED" ]; then
+            exit 0
+          fi
+          echo "Found new corpus entry: $UNTRACKED"
+          echo "file=$UNTRACKED" >> $GITHUB_OUTPUT
+          echo "name=$(basename $UNTRACKED)" >> $GITHUB_OUTPUT
+          echo "package=$(echo ${{ matrix.package }} | sed 's/\//_/g')" >> $GITHUB_OUTPUT
+          echo "function=${{ matrix.function }}" >> $GITHUB_OUTPUT
+
+      - name: Upload corpus entry
+        id: artifact
+        if: ${{ failure() && steps.new-entry.outputs.file != '' }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: failure-${{ steps.new-entry.outputs.package }}-${{ steps.new-entry.outputs.function }}
+          path: ${{ steps.new-entry.outputs.file }}
+
+      - name: Create new issue
+        if: ${{ failure() && steps.new-entry.outputs.file != '' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const failureName = "${{ steps.new-entry.outputs.name }}";
+            const issueTitle = `${{ matrix.package }}: ${{ matrix.function }} failed (${failureName})`;
+
+            // Look for existing issue first with the same title.
+            const issues = await github.rest.search.issuesAndPullRequests({
+              q: `is:issue is:open repo:${context.repo.owner}/${context.repo.repo} in:title "${failureName}"`
+            })
+            console.log(issues);
+            const issue = issues.data.items.find((issue) => issue.title === issue.title);
+            if (issue) {
+              return;
+            }
+
+            // Create a new issue.
+            await github.rest.issues.create({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              title: issueTitle,
+              body: `
+            A new fuzz test failure was found in <code>${{ matrix.package }}</code>.
+
+            To reproduce the failure locally, run the following command using the GitHub CLI to download the corpus entry:
+
+            <pre lang="bash">gh run download --repo ${{ github.repository }} ${{ github.run_id }} -n failure-${{ steps.new-entry.outputs.package }}-${{ steps.new-entry.outputs.function }} --dir ${{ matrix.package }}/testdata/fuzz/${{ matrix.function }}</pre>
+
+            When opening a PR with the fix, please include in the corpus entry in your commit to prevent regressions.
+
+            [Link to failed run](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})
+            `,
+
+              labels: ['bug'],
+            })