tasks/eval: use regex to match labels on word boundary

This prevents a PR named "libsdl: xyz" being tagged as "6.topic: bsd".

This is slightly more robust than simply checking if the strings
"bsd" or "darwin" or "macos" are present in the title.

Cargo.lock

@@ -17,6 +17,15 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "amq-protocol"
 version = "6.0.3"
@@ -927,6 +936,7 @@ dependencies = [
  "lru-cache",
  "md5",
  "nom 4.2.3",
+ "regex",
  "separator",
  "serde",
  "serde_derive",
@@ -1218,6 +1228,8 @@ version = "1.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
 dependencies = [
+ "aho-corasick",
+ "memchr",
  "regex-syntax",
 ]
 

ofborg/Cargo.toml

@@ -19,6 +19,7 @@ lapin = "1.0.0"
 lru-cache = "0.1.1"
 md5 = "0.3.5"
 nom = "4.0.0-beta3"
+regex = "1.5.4"
 separator = "0.4.1"
 serde = "1.0"
 serde_derive = "1.0"

ofborg/src/tasks/eval/nixpkgs.rs

@@ -21,6 +21,7 @@ use hubcaps::checks::{CheckRunOptions, CheckRunState, Conclusion, Output};
 use hubcaps::gists::Gists;
 use hubcaps::issues::{Issue, IssueRef};
 use hubcaps::repositories::Repository;
+use regex::Regex;
 use tracing::{info, warn};
 use uuid::Uuid;
 
@@ -32,6 +33,19 @@ const TITLE_LABELS: [(&str, &str); 3] = [
     ("macos", "6.topic: darwin"),
 ];
 
+fn label_from_title(title: &str) -> Vec<String> {
+    let labels: Vec<_> = TITLE_LABELS
+        .iter()
+        .filter(|(word, _label)| {
+            let re = Regex::new(&format!("\\b{}\\b", word)).unwrap();
+            re.is_match(&title)
+        })
+        .map(|(_word, label)| (*label).into())
+        .collect();
+
+    labels
+}
+
 pub struct NixpkgsStrategy<'a> {
     job: &'a EvaluationJob,
     pull: &'a hubcaps::pulls::PullRequest<'a>,
@@ -78,11 +92,7 @@ impl<'a> NixpkgsStrategy<'a> {
             Err(_) => return,
         };
 
-        let labels: Vec<_> = TITLE_LABELS
+        let labels = label_from_title(&title);
-            .iter()
-            .filter(|(word, _label)| title.contains(word))
-            .map(|(_word, label)| (*label).into())
-            .collect();
 
         if labels.is_empty() {
             return;
@@ -662,4 +672,32 @@ mod tests {
             expect
         );
     }
+
+    #[test]
+    fn test_label_platform_from_title() {
+        assert_eq!(
+            label_from_title("libsdl: 1.0.0 -> 1.1.0"),
+            Vec::<String>::new()
+        );
+        assert_eq!(
+            label_from_title("fix build on bsd"),
+            vec![String::from("6.topic: bsd")]
+        );
+        assert_eq!(
+            label_from_title("fix build on darwin"),
+            vec![String::from("6.topic: darwin")]
+        );
+        assert_eq!(
+            label_from_title("fix build on macos"),
+            vec![String::from("6.topic: darwin")]
+        );
+        assert_eq!(
+            label_from_title("fix build on bsd and darwin").sort(),
+            vec![
+                String::from("6.topic: darwin"),
+                String::from("6.topic: bsd")
+            ]
+            .sort()
+        );
+    }
 }