Add honggfuzz as an alternative fuzzer

Closes GH-55.

Reviewed-by: Titus Wormer <tituswormer@gmail.com>

Author: ChristianMurphy

.gitignore

@@ -8,3 +8,5 @@ unicode-data.txt
 fuzz/target
 fuzz/corpus
 fuzz/artifacts
+fuzz/hfuzz_target
+fuzz/hfuzz_workspace

fuzz/Cargo.toml

@@ -10,6 +10,7 @@ cargo-fuzz = true
 
 [dependencies]
 libfuzzer-sys = "0.4"
+honggfuzz = "0.5"
 
 [dependencies.markdown]
 path = ".."
@@ -19,7 +20,13 @@ path = ".."
 members = ["."]
 
 [[bin]]
-name = "markdown"
-path = "fuzz_targets/markdown.rs"
+name = "markdown_libfuzz"
+path = "fuzz_targets/markdown_libfuzz.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "markdown_honggfuzz"
+path = "fuzz_targets/markdown_honggfuzz.rs"
+test = false
+doc = false

fuzz/fuzz_targets/markdown_honggfuzz.rs

@@ -0,0 +1,15 @@
+use honggfuzz::fuzz;
+
+fn main() {
+    loop {
+        fuzz!(|data: &[u8]| {
+            if let Ok(s) = std::str::from_utf8(data) {
+                let _ = markdown::to_html(s);
+                let _ = markdown::to_html_with_options(s, &markdown::Options::gfm());
+                let _ = markdown::to_mdast(s, &markdown::ParseOptions::default());
+                let _ = markdown::to_mdast(s, &markdown::ParseOptions::gfm());
+                let _ = markdown::to_mdast(s, &markdown::ParseOptions::mdx());
+            }
+        });
+    }
+}

fuzz/fuzz_targets/markdown.rs renamed to fuzz/fuzz_targets/markdown_libfuzz.rs

@@ -268,7 +268,9 @@ The following bash scripts are useful when working on this project:
 *   fuzz:
     ```sh
     cargo install cargo-fuzz
-    cargo +nightly fuzz run markdown
+    cargo install honggfuzz
+    cargo +nightly fuzz run markdown_libfuzz
+    cargo hfuzz run markdown_honggfuzz
     ```
 
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