Add fuzzing

.github/workflows/rust.yml

@@ -64,6 +64,47 @@ jobs:
     - name: Lint code with clippy
       run: cargo clippy
 
+  fuzzing:
+    if: ${{ github.ref == 'main' || !github.event.pull_request.draft || contains(github.event.pull_request.labels.*.name, 'fuzz-me') }}
+    needs: validity
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    continue-on-error: true
+    strategy:
+      matrix:
+        fuzz-target: [source_roundtrip_naive]
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions/cache@v4
+        with:
+          path: ${{ env.CACHE_PATHS }}
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Install latest nightly and set it as default
+        run: |
+          rustup install nightly
+          rustup default nightly
+
+      - name: Install cargo-fuzz
+        run: cargo install --git https://github.com/rust-fuzz/cargo-fuzz.git
+
+      - name: Run fuzzing
+        env:
+          SHORT_CIRCUIT: true
+        run: |
+          if ${{ env.SHORT_CIRCUIT }}; then
+            cargo fuzz run -s none ${{ matrix.fuzz-target }} -- -timeout=10 -use_value_profile=1 -max_total_time=120
+          else
+            cargo fuzz run -s none ${{ matrix.fuzz-target }} -- -timeout=10 -use_value_profile=1 -max_total_time=300 -fork=1 -ignore_crashes=1
+
+            # if test -d fuzz/artifacts; then 
+            #   find fuzz/artifacts -type f -print -exec xxd {} \; -exec cargo fuzz fmt -s none module_roundtrip_structured {} \;; false; 
+            # fi
+          fi
+        working-directory: fuzz
+
   publish-ability:
     runs-on: ubuntu-latest
     if: false

fuzz/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "simple-json-parser-fuzz"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[dependencies]
+libfuzzer-sys = "0.4"
+
+[dependencies.simple-json-parser]
+path = ".."
+
+[package.metadata]
+cargo-fuzz = true
+
+[[bin]]
+name = "source_roundtrip_naive"
+path = "fuzz_targets/source_roundtrip_naive.rs"
+test = false
+doc = false

fuzz/fuzz_targets/source_roundtrip_naive.rs

@@ -0,0 +1,21 @@
+#![no_main]
+
+use libfuzzer_sys::{fuzz_target, Corpus};
+use simple_json_parser::parse;
+use std::str;
+
+/// `do_fuzz` will take an arbitrary string, parse once and see if it returned a valid source
+fn do_fuzz(data: &str) -> Corpus {
+    let input = data.trim_start();
+
+    let result = parse(&input, |_keys, _value| {});
+
+    match result {
+        Ok(_value) => Corpus::Keep,
+        Err(_err) => Corpus::Reject,
+    }
+}
+
+fuzz_target!(|data: &str| {
+    do_fuzz(data);
+});