From fa0cb103d4d7b903688f41b15496e269be4c1c0b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sandra=20Tatarevi=C4=87ov=C3=A1?=
<sandra.tatarevicova@windy.com>
Date: Wed, 21 Feb 2024 08:39:18 +0100
Subject: [PATCH] feat: add support for parsing boolean strings
---
src/TransformOperationExecutor.ts | 6 +++++-
src/constants/default-options.constant.ts | 1 +
.../class-transformer-options.interface.ts | 8 ++++++++
test/functional/implicit-type-declarations.spec.ts | 12 +++++++++++-
4 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/src/TransformOperationExecutor.ts b/src/TransformOperationExecutor.ts
index 0533f03df..c64b14410 100644
--- a/src/TransformOperationExecutor.ts
+++ b/src/TransformOperationExecutor.ts
@@ -107,7 +107,11 @@ export class TransformOperationExecutor {
return Number(value);
} else if (targetType === Boolean && !isMap) {
if (value === null || value === undefined) return value;
- return Boolean(value);
+ if (this.options.parseBooleanStrings && typeof value === 'string') {
+ return value.toLowerCase() === 'true' || value === '1';
+ } else {
+ return Boolean(value);
+ }
} else if ((targetType === Date || value instanceof Date) && !isMap) {
if (value instanceof Date) {
return new Date(value.valueOf());
diff --git a/src/constants/default-options.constant.ts b/src/constants/default-options.constant.ts
index b2f5f3b76..10030bc32 100644
--- a/src/constants/default-options.constant.ts
+++ b/src/constants/default-options.constant.ts
@@ -10,6 +10,7 @@ export const defaultOptions: Partial<ClassTransformOptions> = {
excludePrefixes: undefined,
exposeDefaultValues: false,
exposeUnsetFields: true,
+ parseBooleanStrings: false,
groups: undefined,
ignoreDecorators: false,
strategy: undefined,
diff --git a/src/interfaces/class-transformer-options.interface.ts b/src/interfaces/class-transformer-options.interface.ts
index 25be8f18e..2f6e6aa05 100644
--- a/src/interfaces/class-transformer-options.interface.ts
+++ b/src/interfaces/class-transformer-options.interface.ts
@@ -76,4 +76,12 @@ export interface ClassTransformOptions {
* DEFAULT: `true`
*/
exposeUnsetFields?: boolean;
+
+ /**
+ * When set to true, boolean fields with string `true` (case insensitive) or `1` as value will be converted to true, other
+ * string values will be converted to false.
+ *
+ * DEFAULT: `false`
+ */
+ parseBooleanStrings?: boolean;
}
diff --git a/test/functional/implicit-type-declarations.spec.ts b/test/functional/implicit-type-declarations.spec.ts
index 889565512..1b1e1a188 100644
--- a/test/functional/implicit-type-declarations.spec.ts
+++ b/test/functional/implicit-type-declarations.spec.ts
@@ -102,6 +102,12 @@ describe('plainToInstance transforms built-in primitive types properly', () => {
@Type()
boolean2: boolean;
+
+ @Type()
+ boolean3: boolean;
+
+ @Type()
+ boolean4: boolean;
}
const result: Example = plainToInstance(
@@ -114,8 +120,10 @@ describe('plainToInstance transforms built-in primitive types properly', () => {
number2: 100,
boolean: 1,
boolean2: 0,
+ boolean3: 'true',
+ boolean4: 'false',
},
- { enableImplicitConversion: true }
+ { enableImplicitConversion: true, parseBooleanStrings: true }
);
it('should recognize and convert to Date', () => {
@@ -140,5 +148,7 @@ describe('plainToInstance transforms built-in primitive types properly', () => {
it('should recognize and convert to boolean', () => {
expect(result.boolean).toBeTruthy();
expect(result.boolean2).toBeFalsy();
+ expect(result.boolean3).toBeTruthy();
+ expect(result.boolean4).toBeFalsy();
});
});