Add Chemin.extract

README.md

@@ -158,6 +158,10 @@ Accepts a `Chemin` and a `pathname` and return `false` or `CheminMatchResult`.
 
 Accepts the same arguments as `Chemin.match` but return `false` if the path does not match or if `rest` is not empty, otherwise it returns the `params` object directly.
 
+### Chemin.extract(chemin)
+
+Accepts a `Chemin` and return an array of all the `Chemin` it contains (as well as teh `Chemin` itself).
+
 ### CheminUtils.splitPathname(pathname)
 
 > Split a pathname and prevent empty parts

src/Chemin.ts

@@ -9,6 +9,7 @@ export const Chemin = {
   is: isPattern,
   match: matchPattern,
   matchExact: matchExactPattern,
+  extract: extractPatterns,
 };
 
 type Part = CheminParams<any, any> | Chemin<any>;
@@ -196,3 +197,17 @@ function stringifyPattern(pattern: Chemin<any>): string {
       .join('/')
   );
 }
+
+function extractPatterns(chemin: Chemin): Array<Chemin> {
+  const result: Array<Chemin> = [chemin];
+  function traverse(current: Part) {
+    if (isPattern(current)) {
+      if (result.indexOf(current) === -1) {
+        result.push(current);
+        current.parts.forEach(traverse);
+      }
+    }
+  }
+  chemin.parts.forEach(traverse);
+  return result;
+}

tests/index.test.ts

@@ -66,3 +66,17 @@ test('serialize correctly', () => {
 
   expect(Chemin.stringify(postAdmin)).toBe('/admin/:userId/post/:postId(number)/edit');
 });
+
+test('extract chemins', () => {
+  const empty = Chemin.create();
+  const post = Chemin.create(empty, P.constant('post'));
+  const postFragment = Chemin.create(post, P.number('postId'));
+  const postAdmin = Chemin.create('admin', P.string('userId'), postFragment, 'edit');
+
+  const result = Chemin.extract(postAdmin);
+  expect(result.length).toBe(4);
+  expect(result[0]).toBe(postAdmin);
+  expect(result[1]).toBe(postFragment);
+  expect(result[2]).toBe(post);
+  expect(result[3]).toBe(empty);
+});