Fix case-insensitivity of internal cache

gfyoung · gfyoung · commit f2f67cbaf9c8 · 2021-11-03T06:41:00.000Z
The internal cache really should be caching the
generated output of the reduce pattern, not
the generated RegExp object, which may not have
the right behavior for "ignorecase"
diff --git a/index.js b/index.js
@@ -288,22 +288,17 @@ const REPLACERS = [
 const regexCache = Object.create(null)
 
 // @param {pattern}
-const makeRegex = (pattern, negative, ignorecase) => {
-  const r = regexCache[pattern]
-  if (r) {
-    return r
-  }
-
-  // const replacers = negative
-  //   ? NEGATIVE_REPLACERS
-  //   : POSITIVE_REPLACERS
+const makeRegex = (pattern, ignorecase) => {
+  let source = regexCache[pattern]
 
-  const source = REPLACERS.reduce(
-    (prev, current) => prev.replace(current[0], current[1].bind(pattern)),
-    pattern
-  )
+  if (!source) {
+    regexCache[pattern] = source = REPLACERS.reduce(
+      (prev, current) => prev.replace(current[0], current[1].bind(pattern)),
+      pattern
+    )
+  }
 
-  return regexCache[pattern] = ignorecase
+  return ignorecase
     ? new RegExp(source, 'i')
     : new RegExp(source)
 }
@@ -352,7 +347,7 @@ const createRule = (pattern, ignorecase) => {
   // >   begin with a hash.
   .replace(REGEX_REPLACE_LEADING_EXCAPED_HASH, '#')
 
-  const regex = makeRegex(pattern, negative, ignorecase)
+  const regex = makeRegex(pattern, ignorecase)
 
   return new IgnoreRule(
     origin,
diff --git a/test/others.js b/test/others.js
@@ -85,6 +85,28 @@ _test('options.ignorecase', t => {
   t.end()
 })
 
+_test('special case: internal cache respects ignorecase', t => {
+  const rule = '*.[jJ][pP]g'
+
+  const ig = ignore({
+    ignorecase: false
+  })
+
+  ig.add(rule)
+
+  t.is(ig.ignores('a.JPG'), false)
+
+  const ig2 = ignore({
+    ignorecase: true
+  })
+
+  ig2.add(rule)
+
+  t.is(ig2.ignores('a.JPG'), true)
+
+  t.end()
+})
+
 _test('special case: invalid paths, throw', t => {
   const ig = ignore()
 
