fix(assertion-matchers): Refactor matcher implementations to consistently use customAssertion for improved consistency and clarity.

ts/namespaces/string.ts

@@ -7,26 +7,44 @@ export class StringMatchers {
   constructor(private assertion: Assertion<string>) {}
 
   toStartWith(prefix: string) {
-    return this.assertion.toStartWith(prefix);
+    return this.assertion.customAssertion(
+      (value) => (value as string).startsWith(prefix),
+      `Expected string to start with "${prefix}"`
+    );
   }
 
   toEndWith(suffix: string) {
-    return this.assertion.toEndWith(suffix);
+    return this.assertion.customAssertion(
+      (value) => (value as string).endsWith(suffix),
+      `Expected string to end with "${suffix}"`
+    );
   }
 
   toInclude(substring: string) {
-    return this.assertion.toInclude(substring);
+    return this.assertion.customAssertion(
+      (value) => (value as string).includes(substring),
+      `Expected string to include "${substring}"`
+    );
   }
 
   toMatch(regex: RegExp) {
-    return this.assertion.toMatch(regex);
+    return this.assertion.customAssertion(
+      (value) => regex.test(value as string),
+      `Expected string to match ${regex}`
+    );
   }
 
   toBeOneOf(values: string[]) {
-    return this.assertion.toBeOneOf(values);
+    return this.assertion.customAssertion(
+      (value) => (values as string[]).includes(value as string),
+      `Expected string to be one of ${JSON.stringify(values)}`
+    );
   }
   /** Length check for strings */
   toHaveLength(length: number) {
-    return this.assertion.toHaveLength(length);
+    return this.assertion.customAssertion(
+      (value) => (value as string).length === length,
+      `Expected string to have length ${length}`
+    );
   }
 }