feat(common): improve extensibility on built-in pipes

nestjs · Apr 24, 2022 · 4ce5877 · 4ce5877
1 parent 1f6fca5
commit 4ce5877
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Showing 3 changed files with 46 additions and 12 deletions.
diff --git a/packages/common/pipes/parse-bool.pipe.ts b/packages/common/pipes/parse-bool.pipe.ts
@@ -48,14 +48,32 @@ export class ParseBoolPipe
     value: string | boolean,
     metadata: ArgumentMetadata,
   ): Promise<boolean> {
-    if (value === true || value === 'true') {
+    if (this.isTrue(value)) {
       return true;
     }
-    if (value === false || value === 'false') {
+    if (this.isFalse(value)) {
       return false;
     }
     throw this.exceptionFactory(
       'Validation failed (boolean string is expected)',
     );
   }
+
+  /**
+   * @param value currently processed route argument
+   * @returns `true` if `value` is said 'true', ie., if it is equal to the boolean
+   * `true` or the string `"true"`
+   */
+  protected isTrue(value: string | boolean): boolean {
+    return value === true || value === 'true';
+  }
+
+  /**
+   * @param value currently processed route argument
+   * @returns `true` if `value` is said 'false', ie., if it is equal to the boolean
+   * `false` or the string `"false"`
+   */
+  protected isFalse(value: string | boolean): boolean {
+    return value === false || value === 'false';
+  }
 }
diff --git a/packages/common/pipes/parse-float.pipe.ts b/packages/common/pipes/parse-float.pipe.ts
@@ -39,15 +39,23 @@ export class ParseFloatPipe implements PipeTransform<string> {
    * @param metadata contains metadata about the currently processed route argument
    */
   async transform(value: string, metadata: ArgumentMetadata): Promise<number> {
-    const isNumeric =
-      ['string', 'number'].includes(typeof value) &&
-      !isNaN(parseFloat(value)) &&
-      isFinite(value as any);
-    if (!isNumeric) {
+    if (!this.isNumeric(value)) {
       throw this.exceptionFactory(
         'Validation failed (numeric string is expected)',
       );
     }
     return parseFloat(value);
   }
+
+  /**
+   * @param value currently processed route argument
+   * @returns `true` if `value` is a valid float number
+   */
+  protected isNumeric(value: string): boolean {
+    return (
+      ['string', 'number'].includes(typeof value) &&
+      !isNaN(parseFloat(value)) &&
+      isFinite(value as any)
+    );
+  }
 }
diff --git a/packages/common/pipes/parse-int.pipe.ts b/packages/common/pipes/parse-int.pipe.ts
@@ -44,15 +44,23 @@ export class ParseIntPipe implements PipeTransform<string> {
    * @param metadata contains metadata about the currently processed route argument
    */
   async transform(value: string, metadata: ArgumentMetadata): Promise<number> {
-    const isNumeric =
-      ['string', 'number'].includes(typeof value) &&
-      /^-?\d+$/.test(value) &&
-      isFinite(value as any);
-    if (!isNumeric) {
+    if (!this.isNumeric(value)) {
       throw this.exceptionFactory(
         'Validation failed (numeric string is expected)',
       );
     }
     return parseInt(value, 10);
   }
+
+  /**
+   * @param value currently processed route argument
+   * @returns `true` if `value` is a valid integer number
+   */
+  protected isNumeric(value: string): boolean {
+    return (
+      ['string', 'number'].includes(typeof value) &&
+      /^-?\d+$/.test(value) &&
+      isFinite(value as any)
+    );
+  }
 }