From 4f791c56822dc9d1645cbe852738056412d5d0e6 Mon Sep 17 00:00:00 2001
From: Valeriy <ValeraS@users.noreply.github.com>
Date: Tue, 28 Jun 2022 23:56:57 +0300
Subject: [PATCH] fix(replaceParams): correctly substitute params with special
 content (#29)

---
 src/replace-params.spec.ts | 26 ++++++++++++++++++++++++++
 src/replace-params.ts      | 28 +++++++++++++++++++---------
 2 files changed, 45 insertions(+), 9 deletions(-)
 create mode 100644 src/replace-params.spec.ts

diff --git a/src/replace-params.spec.ts b/src/replace-params.spec.ts
new file mode 100644
index 0000000..86bd1f5
--- /dev/null
+++ b/src/replace-params.spec.ts
@@ -0,0 +1,26 @@
+import {replaceParams} from './replace-params';
+
+describe('replaceParams', () => {
+    it('should substitute params', () => {
+        expect(replaceParams('{{test}}', {test: 'text'})).toBe('text');
+        expect(replaceParams('{{test}}{{test}}', {test: 'text'})).toBe('texttext');
+        expect(replaceParams('some {{test}}', {test: 'text'})).toBe('some text');
+        expect(replaceParams('some {{test}} text', {test: 'cool'})).toBe('some cool text');
+        expect(replaceParams('{{test}} text', {test: 'cool'})).toBe('cool text');
+        expect(replaceParams('some {{test}} text {{test2}} !!', {test: 'cool', test2: 'hey'})).toBe('some cool text hey !!');
+    });
+    it('should not replace missing params', () => {
+        expect(replaceParams('{{test}}', {})).toBe('{{test}}');
+        expect(replaceParams('some {{test}}', {})).toBe('some {{test}}');
+        expect(replaceParams('some {{test}} text', {})).toBe('some {{test}} text');
+        expect(replaceParams('{{test}} text', {})).toBe('{{test}} text');
+        expect(replaceParams('some {{test}} text {{test2}} !!', {test: 'cool'})).toBe('some cool text {{test2}} !!');
+    })
+    it('should correctly substitute content with specials', () => {
+        expect(replaceParams('{{test}}', {test: '$'})).toBe('$');
+        expect(replaceParams('{{test}}', {test: '$$'})).toBe('$$');
+        expect(replaceParams('{{test1}} {{test2}}', {test1: '{{test2}}', test2: '{{test3}}', test3: 'content'})).toBe(
+            '{{test2}} {{test3}}',
+        );
+    });
+});
diff --git a/src/replace-params.ts b/src/replace-params.ts
index 3e3d95f..d2106e7 100644
--- a/src/replace-params.ts
+++ b/src/replace-params.ts
@@ -1,18 +1,28 @@
 import {Params} from './types';
 
+const PARAM_REGEXP = /{{(.*?)}}/g;
+
 export function replaceParams(keyValue: string, params: Params): string {
-    let result = keyValue;
+    let result = '';
 
-    Object.keys(params).forEach((param) => {
-        let replacer = params[param];
-        if (typeof replacer === 'string' && replacer.indexOf('$') > -1) {
-            // заменить все одиночные символы '$' на '$$'
-            replacer = replacer.replace(/(?:([^$])\$|^\$)(?!\$)/g, '$1$$$$');
+    let lastIndex = (PARAM_REGEXP.lastIndex = 0);
+    let match;
+    while ((match = PARAM_REGEXP.exec(keyValue))) {
+        if (lastIndex !== match.index) {
+            result += keyValue.slice(lastIndex, match.index);
         }
+        lastIndex = PARAM_REGEXP.lastIndex;
 
-        // eslint-disable-next-line security/detect-non-literal-regexp
-        result = result.replace(new RegExp(`({{${param}}})`, 'g'), replacer)
-    });
+        const [all, key] = match;
+        if (Object.prototype.hasOwnProperty.call(params, key)) {
+            result += params[key];
+        } else {
+            result += all;
+        }
+    }
+    if (lastIndex < keyValue.length) {
+        result += keyValue.slice(lastIndex);
+    }
 
     return result;
 }