Fix makeRe() when partial: true

Brian Huf · isaacs · commit 9f4a4ff09093 · 2025-10-28T15:03:24.000-07:00
PR-URL: #272 Credit: @BrianHuf Close: #272 Reviewed-by: @isaacs
diff --git a/src/index.ts b/src/index.ts
@@ -1080,7 +1080,20 @@ export class Minimatch {
             pp[i + 1] = GLOBSTAR
           }
         })
-        return pp.filter(p => p !== GLOBSTAR).join('/')
+        const filtered = pp.filter(p => p !== GLOBSTAR)
+        
+        // For partial matches, we need to make the pattern match
+        // any prefix of the full path. We do this by generating
+        // alternative patterns that match progressively longer prefixes.
+        if (this.partial && filtered.length >= 1) {
+          const prefixes: string[] = []
+          for (let i = 1; i <= filtered.length; i++) {
+            prefixes.push(filtered.slice(0, i).join('/'))
+          }
+          return '(?:' + prefixes.join('|') + ')'
+        }
+        
+        return filtered.join('/')
       })
       .join('|')
 
@@ -1090,6 +1103,11 @@ export class Minimatch {
     // must match entire pattern
     // ending in a * or ** will make it less strict.
     re = '^' + open + re + close + '$'
+    
+    // In partial mode, '/' should always match as it's a valid prefix for any pattern
+    if (this.partial) {
+      re = '^(?:\\/|' + open + re.slice(1, -1) + close + ')$'
+    }
 
     // can match anything, as long as it's not this.
     if (this.negate) re = '^(?!' + re + ').+$'
diff --git a/test/partial.js b/test/partial.js
@@ -5,3 +5,7 @@ t.equal(mm('/a/b/c', '/*/b/x/y/z', { partial: true }), false)
 t.equal(mm('/', 'x', { partial: true }), true)
 const m = new mm.Minimatch('/*/b/x/y/z')
 t.equal(m.match('/a/b', true), true)
+
+t.equal(mm.makeRe('/*/b/x/y/z', { partial: true }).test('/a/b'), true);
+t.equal(mm.makeRe('/*/b/x/y/z', { partial: true }).test('/a/b/c'), false);
+t.equal(mm.makeRe('x', { partial: true }).test('/'), true);
