fix partial matching of globstar patterns

Fix: #284

Author: isaacs

src/index.ts

@@ -951,7 +951,11 @@ export class Minimatch {
     // split the pattern up into globstar-delimited sections
     // the tail has to be at the end, and the others just have
     // to be found in order from the head.
-    const [head, body, tail] = [
+    const [head, body, tail] = partial ? [
+      pattern.slice(patternIndex, firstgs),
+      pattern.slice(firstgs + 1),
+      [],
+    ] : [
       pattern.slice(patternIndex, firstgs),
       pattern.slice(firstgs + 1, lastgs),
       pattern.slice(lastgs + 1),
@@ -1018,7 +1022,8 @@ export class Minimatch {
           return false
         }
       }
-      return sawSome
+      // in partial mode, we just need to get past all file parts
+      return partial || sawSome
     }
 
     // now we know that there's one or more body sections, which can
@@ -1135,7 +1140,7 @@ export class Minimatch {
       fileIndex++
     }
     // walked off. no point continuing
-    return null
+    return partial || null
   }
 
   #matchOne(

test/partial.js

@@ -0,0 +1,27 @@
+import t from 'tap'
+import { minimatch as mm } from '../src/index.js'
+import type { MMRegExp } from '../src/index.js'
+
+t.equal(mm('/a/b', '/*/b/x/y/z', { partial: true }), true)
+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('/b/c/d/a', '/**/a/b/c', { partial: true }), true)
+t.equal(mm('/b/c/d/a', '/**/a/b/c/**', { partial: true }), true)
+
+t.equal(mm('a', 'a/**', { partial: true }), true)
+t.equal(mm('a', '**', { partial: true }), true)
+t.equal(mm('b/a', 'a/**', { partial: true }), false)
+t.equal(mm('/b/c/d/a', '/**/a/**/b/c/**', { partial: true }), true)
+t.equal(mm('/b/c/d/a', '/**/a/**', { partial: true }), true)
+
+t.equal(
+  (mm.makeRe('/*/b/x/y/z', { partial: true }) as MMRegExp).test('/a/b'),
+  true,
+)
+t.equal(
+  (mm.makeRe('/*/b/x/y/z', { partial: true }) as MMRegExp).test('/a/b/c'),
+  false,
+)
+t.equal((mm.makeRe('x', { partial: true }) as MMRegExp).test('/'), true)