Merge pull request #1795 from simlu/dev

fix: handling sparse arrays

Author: simlu

README.md

@@ -4,7 +4,7 @@
 [![NPM](https://img.shields.io/npm/v/object-scan.svg)](https://www.npmjs.com/package/object-scan)
 [![Downloads](https://img.shields.io/npm/dt/object-scan.svg)](https://www.npmjs.com/package/object-scan)
 [![Size](https://shields.io/badge/min%20+%20gz-5.00%20KB-informational)](https://bundlephobia.com/package/object-scan)
-[![Test Ratio](https://shields.io/badge/test%20:%20code-9.9%20:%201-informational)](./test/readme/replace-variables/ratio-badge.js)
+[![Test Ratio](https://shields.io/badge/test%20:%20code-9.8%20:%201-informational)](./test/readme/replace-variables/ratio-badge.js)
 
 Traverse object hierarchies using matching and callbacks.
 
@@ -75,7 +75,8 @@ objectScan(['a.*.f'], { joined: true })(haystack);
    <a href="#81-traversal-order"><img alt="Traversal Order" src="https://shields.io/badge/8.1.-Traversal%20Order-c96c01?style=flat-square"></a><br>
    <a href="#82-empty-string"><img alt="Empty String" src="https://shields.io/badge/8.2.-Empty%20String-c96c01?style=flat-square"></a><br>
    <a href="#83-array-string-keys"><img alt="Array String Keys" src="https://shields.io/badge/8.3.-Array%20String%20Keys-c96c01?style=flat-square"></a><br>
-   <a href="#84-internals"><img alt="Internals" src="https://shields.io/badge/8.4.-Internals-c96c01?style=flat-square"></a></details>
+   <a href="#84-sparse-arrays"><img alt="Sparse Arrays" src="https://shields.io/badge/8.4.-Sparse%20Arrays-c96c01?style=flat-square"></a><br>
+   <a href="#85-internals"><img alt="Internals" src="https://shields.io/badge/8.5.-Internals-c96c01?style=flat-square"></a></details>
 
 ## 3. Features
 
@@ -1594,7 +1595,24 @@ objectScan(['**'], {
 ```
 </details>
 
-### 8.4. Internals
+### 8.4. Sparse Arrays
+
+Only set keys are traversed for spare Arrays.
+
+<details><summary> <code>['**']</code> <em>(empty entries skipped)</em> </summary>
+
+<!-- eslint-disable no-undef -->
+```js
+const haystack = (() => { const r = []; r[1] = 'a'; return r; })();
+objectScan(['**'], {
+  joined: true,
+  rtn: 'entry'
+})(haystack);
+// => [ [ '[1]', 'a' ] ]
+```
+</details>
+
+### 8.5. Internals
 
 This library has been designed around performance as a core feature.
 
@@ -1611,7 +1629,7 @@ Conceptually this package works as follows:
 
 1. During initialization the needles are parsed and built into a search tree.
 Various information is pre-computed and stored for every node.
-Finally the search function is returned.
+Finally, the search function is returned.
 
 2. When the search function is invoked, the input is traversed simultaneously with
 the relevant nodes of the search tree. Processing multiple search tree branches

src/core/find.js

@@ -152,7 +152,9 @@ export default (haystack_, search_, ctx) => {
       && haystack instanceof Object
     ) {
       const isArray = Array.isArray(haystack);
-      const keys = isArray ? haystack.map((_, i) => i) : Object.keys(haystack);
+      const keys = isArray
+        ? haystack.map((_, i) => i).filter(() => true)
+        : Object.keys(haystack);
       if (!isArray && ctx.compareFn) {
         keys.sort(ctx.compareFn(kwargs));
       }

test/index.spec.js

@@ -1052,4 +1052,15 @@ describe('Testing Find', () => {
     })(data);
     expect(r).to.deep.equal([[[1], 'b'], [[0], 'a']]);
   });
+
+  it('Testing sparse array keys', () => {
+    const data = [];
+    data[1] = 'a';
+    data[2] = undefined;
+    const r = objectScan(['**'], {
+      joined: false,
+      rtn: 'entry'
+    })(data);
+    expect(r).to.deep.equal([[[2], undefined], [[1], 'a']]);
+  });
 });

test/readme/README.template.md

@@ -1118,6 +1118,17 @@ rtn: 'entry'
 comment: str key skipped
 </example></pre>
 
+### Sparse Arrays
+
+Only set keys are traversed for spare Arrays.
+
+<pre><example>
+haystack: (() => { const r = []; r[1] = 'a'; return r; })()
+needles: ['**']
+rtn: 'entry'
+comment: empty entries skipped
+</example></pre>
+
 ### Internals
 
 This library has been designed around performance as a core feature.
@@ -1135,7 +1146,7 @@ Conceptually this package works as follows:
 
 1. During initialization the needles are parsed and built into a search tree.
 Various information is pre-computed and stored for every node.
-Finally the search function is returned.
+Finally, the search function is returned.
 
 2. When the search function is invoked, the input is traversed simultaneously with
 the relevant nodes of the search tree. Processing multiple search tree branches