From 22204a2f479dbcef37db707de367a5b17f46a3d6 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Thu, 3 Sep 2020 17:45:32 +0300
Subject: [PATCH] feat: add interpolate utility fn to replace placeholders

---
 .../core/src/lib/tests/string-utils.spec.ts   | 26 ++++++++++++++++++-
 .../core/src/lib/utils/string-utils.ts        |  6 +++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/npm/ng-packs/packages/core/src/lib/tests/string-utils.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/string-utils.spec.ts
index a0642e43ee..c2f7a3c601 100644
--- a/npm/ng-packs/packages/core/src/lib/tests/string-utils.spec.ts
+++ b/npm/ng-packs/packages/core/src/lib/tests/string-utils.spec.ts
@@ -1,4 +1,4 @@
-import { createTokenParser } from '../utils/string-utils';
+import { createTokenParser, interpolate } from '../utils/string-utils';
 
 describe('String Utils', () => {
   describe('#createTokenParser', () => {
@@ -19,4 +19,28 @@ describe('String Utils', () => {
       },
     );
   });
+
+  describe('#interpolate', () => {
+    test.each`
+      text                                         | params                          | expected
+      ${'This is {0} and {1} example.'}            | ${['foo', 'bar']}               | ${'This is foo and bar example.'}
+      ${'This is {1} and {0} example.'}            | ${['foo', 'bar']}               | ${'This is bar and foo example.'}
+      ${'This is {0} and {0} example.'}            | ${['foo', 'bar']}               | ${'This is foo and foo example.'}
+      ${'This is {1} and {1} example.'}            | ${['foo', 'bar']}               | ${'This is bar and bar example.'}
+      ${'This is "{0}" and "{1}" example.'}        | ${['foo', 'bar']}               | ${'This is foo and bar example.'}
+      ${"This is '{1}' and '{0}' example."}        | ${['foo', 'bar']}               | ${'This is bar and foo example.'}
+      ${'This is { 0 } and {0} example.'}          | ${['foo', 'bar']}               | ${'This is foo and foo example.'}
+      ${'This is {1} and {  1  } example.'}        | ${['foo', 'bar']}               | ${'This is bar and bar example.'}
+      ${'This is {0}, {3}, {1}, and {2} example.'} | ${['foo', 'bar', 'baz', 'qux']} | ${'This is foo, qux, bar, and baz example.'}
+      ${'This is {0} with 0 example.'}             | ${['foo']}                      | ${'This is foo with 0 example.'}
+      ${'This is {0} and {1} example.'}            | ${['foo']}                      | ${'This is foo and {1} example.'}
+      ${'This is {0} and {1} example.'}            | ${[]}                           | ${'This is {0} and {1} example.'}
+      ${'This is {0} example.'}                    | ${[null]}                       | ${'This is {0} example.'}
+    `(
+      'should return $expected when text is $text and params are $params',
+      ({ text, params, expected }) => {
+        expect(interpolate(text, params)).toBe(expected);
+      },
+    );
+  });
 });
diff --git a/npm/ng-packs/packages/core/src/lib/utils/string-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/string-utils.ts
index 00db697325..7404dceab7 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/string-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/string-utils.ts
@@ -15,3 +15,9 @@ export function createTokenParser(format: string) {
     }, {} as Record<string, string[]>);
   };
 }
+
+export function interpolate(text: string, params: string[]) {
+  return text
+    .replace(/(['"]?\{\s*(\d+)\s*\}['"]?)/g, (_, match, digit) => params[digit] ?? match)
+    .replace(/\s+/g, ' ');
+}