Make CI fuzzing a container task

.github/workflows/fuzz.yaml

@@ -22,23 +22,28 @@ jobs:
     name: Parser fuzzing
     runs-on: ubuntu-latest
     timeout-minutes: 25
+    # Run in a container because we had some issues reproducing failures
+    container:
+      image: node:lts-slim
+    env:
+      # Just 10 minutes as a sanity check, should run longer locally.
+      # For whatever reason, this time is always wayyyy exceeded
+      # (hence the longer workflow timeout)
+      FUZZ_TOTAL_TIME: 600
     steps:
       - uses: actions/checkout@v4
-      - uses: taiki-e/install-action@just
-      - name: Get npm cache directory
-        id: npm-cache-dir
-        shell: bash
-        run: echo "dir=$(npm config get cache)" >> ${GITHUB_OUTPUT}
-      - uses: actions/cache@v4
-        id: npm-cache
-        with:
-          path: ${{ steps.npm-cache-dir.outputs.dir }}
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: ${{ runner.os }}-node-
       - run: |
-          npm --version
-          npx --version
-          clang --version
+          if [ -f /.dockerenv ]; then
+              echo "Running in docker"
+          else
+              echo "Not in a docker container!"
+              exit 1
+          fi
+
+          apt-get update
+          apt-get install -y clang curl make g++ git
+          curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh |
+            bash -s -- --to /usr/bin
       - run: just setup
       - run: just fuzz
       - name: Print failures

justfile

@@ -8,6 +8,7 @@ general_cflags := "-Wall -Werror --pedantic -Wno-format-pedantic"
 
 # FIXME: there are errors running with ASAN, we ideally want `,address` here
 fuzzer_flags := env("FUZZER_FLAGS", "-fsanitize=fuzzer,undefined")
+fuzz_time := env("FUZZ_TOTAL_TIME", "1200")
 
 # Source files needed to build a parser
 parser_sources := src + "/scanner.c " + src + "/parser.c " + ts_src + "/lib/src/lib.c"
@@ -53,7 +54,11 @@ setup:
 	check_installed clang-tidy
 	check_installed clang-format
 
-	npm install --include=dev
+	if which npm > /dev/null; then
+		npm install --include=dev
+	else
+		echo "npm not found: skipping install"
+	fi
 
 # Lint with more minimal dependencies that can be run during pre-commit
 _lint-min: tree-sitter-clone configure-compile-database
@@ -312,7 +317,7 @@ fuzz *extra-args: (gen "--debug-build") tree-sitter-clone _out-dirs
 
 	printf "$cache_key" > "$keyfile"
 
-	fuzzer_flags="-artifact_prefix=$artifacts -timeout=20 -max_total_time=1200 -jobs={{ nproc }}"
+	fuzzer_flags="-artifact_prefix=$artifacts -timeout=20 -max_total_time={{ fuzz_time }} -jobs={{ nproc }}"
 
 	echo "Starting fuzzing at $(date -u -Is)"
 	LD_LIBRARY_PATH="{{ts_src}}" "{{ fuzz_out }}" "$corpus" $fuzzer_flags {{ extra-args }}