ci(fuzz): adopt ClusterFuzzLite for continuous fuzzing on PRs

.clusterfuzzlite/Dockerfile

@@ -0,0 +1,6 @@
+# ClusterFuzzLite build container: compiles the repo's native Go fuzz targets
+# with the OSS-Fuzz toolchain. See https://google.github.io/clusterfuzzlite/
+FROM gcr.io/oss-fuzz-base/base-builder-go:v1
+COPY . $SRC/structalign
+COPY .clusterfuzzlite/build.sh $SRC/build.sh
+WORKDIR $SRC/structalign

.clusterfuzzlite/build.sh

@@ -0,0 +1,12 @@
+#!/bin/bash -eu
+# Build the repo's native Go fuzz targets (go test -fuzz style) as libFuzzer
+# binaries via the OSS-Fuzz toolchain's compile_native_go_fuzzer helper.
+# Usage: compile_native_go_fuzzer <import path> <FuzzFunc> <output binary>
+
+# The rewrite shim used by compile_native_go_fuzzer; added to go.mod only
+# inside the build container, never in the repo.
+go get github.com/AdamKorcz/go-118-fuzz-build/testing
+
+compile_native_go_fuzzer github.com/peczenyj/structalign/internal/match FuzzMatchAny fuzz_match_any
+compile_native_go_fuzzer github.com/peczenyj/structalign/internal/match FuzzSplitCSV fuzz_split_csv
+compile_native_go_fuzzer github.com/peczenyj/structalign/internal/ui FuzzTruncPad fuzz_trunc_pad

.clusterfuzzlite/project.yaml

@@ -0,0 +1 @@
+language: go

.github/workflows/cflite_pr.yml

@@ -0,0 +1,42 @@
+name: ClusterFuzzLite PR fuzzing
+
+on:
+  pull_request:
+    paths:
+      - "**.go"
+      - "go.mod"
+      - "go.sum"
+      - ".clusterfuzzlite/**"
+      - ".github/workflows/cflite_pr.yml"
+
+permissions:
+  contents: read
+
+jobs:
+  fuzz:
+    name: fuzz (${{ matrix.sanitizer }})
+    runs-on: ubuntu-latest
+    concurrency:
+      group: ${{ github.workflow }}-${{ matrix.sanitizer }}-${{ github.ref }}
+      cancel-in-progress: true
+    strategy:
+      fail-fast: false
+      matrix:
+        sanitizer: [address]
+    steps:
+      - name: Build fuzzers (${{ matrix.sanitizer }})
+        id: build
+        uses: google/clusterfuzzlite/actions/build_fuzzers@884713a6c30a92e5e8544c39945cd7cb630abcd1 # v1
+        with:
+          language: go
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          sanitizer: ${{ matrix.sanitizer }}
+
+      - name: Run fuzzers (${{ matrix.sanitizer }})
+        id: run
+        uses: google/clusterfuzzlite/actions/run_fuzzers@884713a6c30a92e5e8544c39945cd7cb630abcd1 # v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          fuzz-seconds: 300
+          mode: code-change
+          sanitizer: ${{ matrix.sanitizer }}

internal/match/fuzz_test.go

@@ -1,18 +1,17 @@
-package match_test
+// Package-internal (not match_test) so ClusterFuzzLite's
+// compile_native_go_fuzzer can rewrite this file: an external test package
+// would clash with the non-test package during the go-118-fuzz-build rewrite.
+package match
 
-import (
-	"testing"
-
-	"github.com/peczenyj/structalign/internal/match"
-)
+import "testing"
 
 func FuzzMatchAny(f *testing.F) {
 	f.Add("Mixed", "Mixed")
 	f.Add("*", "Mixed")
 	f.Add("", "Mixed")
 
 	f.Fuzz(func(t *testing.T, pattern string, name string) {
-		_ = match.MatchAny([]string{pattern}, name)
+		_ = MatchAny([]string{pattern}, name)
 	})
 }
 
@@ -22,6 +21,6 @@ func FuzzSplitCSV(f *testing.F) {
 	f.Add("")
 
 	f.Fuzz(func(t *testing.T, s string) {
-		_ = match.SplitCSV(s)
+		_ = SplitCSV(s)
 	})
 }