chore: add parse pr bench

Author: not-matthias

crates/divan_compat/examples/Cargo.toml

@@ -44,3 +44,7 @@ harness = false
 [[bench]]
 name = "counters"
 harness = false
+
+[[bench]]
+name = "parse_pr"
+harness = false

crates/divan_compat/examples/benches/parse_pr.rs

@@ -0,0 +1,94 @@
+//! Parse PR benchmark - equivalent of the TypeScript version
+
+use divan::black_box;
+
+fn main() {
+    divan::main();
+}
+
+#[derive(Clone)]
+struct PullRequest {
+    #[allow(dead_code)]
+    number: u32,
+    title: String,
+    body: String,
+}
+
+fn send_event(number_of_operations: usize) {
+    for i in 0..number_of_operations {
+        let mut a = i;
+        a = a + 1;
+        let _ = black_box(a);
+    }
+}
+
+fn log_metrics(number_of_operations: usize, number_of_deep_operations: usize) {
+    for _ in 0..number_of_operations {
+        for j in 0..number_of_operations {
+            let mut a = j;
+            a = a + 1;
+            a = a + 1;
+            let _ = black_box(a);
+        }
+        send_event(number_of_deep_operations);
+    }
+}
+
+fn parse_title(title: &str) {
+    log_metrics(10, 10);
+    modify_title(title);
+}
+
+fn modify_title(title: &str) {
+    for i in 0..100 {
+        let mut a = i;
+        a = a + 1 + title.len();
+        let _ = black_box(a);
+    }
+}
+
+fn prepare_parsing_body(body: &str) {
+    for i in 0..100 {
+        let mut a = i;
+        a = a + 1;
+        let _ = black_box(a);
+    }
+    parse_body(body);
+}
+
+fn parse_body(body: &str) {
+    log_metrics(10, 10);
+    for i in 0..200 {
+        let mut a = i;
+        a = a + 1;
+        let _ = black_box(a);
+    }
+    parse_issue_fixed(body);
+}
+
+fn parse_issue_fixed(body: &str) -> Option<u32> {
+    const PREFIX: &str = "fixes #";
+    let index = body.find(PREFIX)?;
+
+    let start = index + PREFIX.len();
+    let mut end = start;
+    while end < body.len() && body[end..=end].chars().next().unwrap().is_ascii_digit() {
+        end += 1;
+    }
+    body[start..end].parse::<u32>().ok()
+}
+
+fn parse_pr(pull_request: &PullRequest) {
+    parse_title(&pull_request.title);
+    prepare_parsing_body(&pull_request.body);
+}
+
+#[divan::bench]
+fn bench_parse_pr() {
+    let pr = black_box(PullRequest {
+        number: 123,
+        title: "Add new feature".to_string(),
+        body: "This PR adds a new feature.\n\nfixes #42\n\nDetails here.".to_string(),
+    });
+    parse_pr(&pr);
+}