Merge pull request #926 from Automattic/fix-cache

hotfix(core): properly store spans in `PatternLinter` cache

Author: elijah-potter

harper-core/src/linting/lint_group.rs

@@ -383,8 +383,8 @@ impl Linter for LintGroup {
             let config_hash = self.hasher_builder.hash_one(&self.config);
             let key = (chunk_chars.into(), config_hash);
 
-            if let Some(hit) = self.chunk_pattern_cache.get(&key) {
-                results.extend(hit.iter().cloned());
+            let mut chunk_results = if let Some(hit) = self.chunk_pattern_cache.get(&key) {
+                hit.clone()
             } else {
                 let mut pattern_lints = Vec::new();
 
@@ -394,10 +394,21 @@ impl Linter for LintGroup {
                     }
                 }
 
+                // Make the spans relative to the chunk start
+                for lint in &mut pattern_lints {
+                    lint.span.pull_by(chunk_span.start);
+                }
+
                 self.chunk_pattern_cache.put(key, pattern_lints.clone());
+                pattern_lints
+            };
 
-                results.append(&mut pattern_lints);
+            // Bring the spans back into document-space
+            for lint in &mut chunk_results {
+                lint.span.push_by(chunk_span.start);
             }
+
+            results.append(&mut chunk_results);
         }
 
         results

harper-core/src/span.rs

@@ -2,6 +2,8 @@ use std::ops::Range;
 
 use serde::{Deserialize, Serialize};
 
+use crate::CharStringExt;
+
 /// A window in a [`char`] sequence.
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, Default, PartialEq, Eq)]
 pub struct Span {
@@ -57,7 +59,14 @@ impl Span {
 
     /// Get the associated content. Will panic if any aspect is invalid.
     pub fn get_content<'a>(&self, source: &'a [char]) -> &'a [char] {
-        self.try_get_content(source).unwrap()
+        match self.try_get_content(source) {
+            Some(v) => v,
+            None => panic!(
+                "Could not get position {:?} within \"{}\"",
+                self,
+                source.to_string()
+            ),
+        }
     }
 
     pub fn get_content_string(&self, source: &[char]) -> String {