fix: apply custom constraint class validation to each item in the array (#295)

Close #260

Author: zd333

Diff for: src/validation/ValidationExecutor.ts

@@ -258,20 +258,54 @@ export class ValidationExecutor {
                         value: value,
                         constraints: metadata.constraints
                     };
-                    const validatedValue = customConstraintMetadata.instance.validate(value, validationArguments);
-                    if (isPromise(validatedValue)) {
-                        const promise = validatedValue.then(isValid => {
-                            if (!isValid) {
+
+                    if (!metadata.each || !(value instanceof Array)) {
+                        const validatedValue = customConstraintMetadata.instance.validate(value, validationArguments);
+                        if (isPromise(validatedValue)) {
+                            const promise = validatedValue.then(isValid => {
+                                if (!isValid) {
+                                    const [type, message] = this.createValidationError(object, value, metadata, customConstraintMetadata);
+                                    errorMap[type] = message;
+                                }
+                            });
+                            this.awaitingPromises.push(promise);
+                        } else {
+                            if (!validatedValue) {
                                 const [type, message] = this.createValidationError(object, value, metadata, customConstraintMetadata);
                                 errorMap[type] = message;
                             }
-                        });
-                        this.awaitingPromises.push(promise);
-                    } else {
-                        if (!validatedValue) {
-                            const [type, message] = this.createValidationError(object, value, metadata, customConstraintMetadata);
-                            errorMap[type] = message;
                         }
+
+                        return;
+                    }
+
+                    // Validation needs to be applied to each array item
+                    const validatedSubValues = value.map((subValue: any) => customConstraintMetadata.instance.validate(subValue, validationArguments));
+                    const validationIsAsync = validatedSubValues
+                        .some((validatedSubValue: boolean | Promise<boolean>) => isPromise(validatedSubValue));
+
+                    if (validationIsAsync) {
+                        // Wrap plain values (if any) in promises, so that all are async
+                        const asyncValidatedSubValues = validatedSubValues
+                            .map((validatedSubValue: boolean | Promise<boolean>) => isPromise(validatedSubValue) ? validatedSubValue : Promise.resolve(validatedSubValue));
+                        const asyncValidationIsFinishedPromise = Promise.all(asyncValidatedSubValues)
+                            .then((flatValidatedValues: boolean[]) => {
+                                const validationResult = flatValidatedValues.every((isValid: boolean) => isValid);
+                                if (!validationResult) {
+                                    const [type, message] = this.createValidationError(object, value, metadata, customConstraintMetadata);
+                                    errorMap[type] = message;
+                                }
+                            });
+
+                        this.awaitingPromises.push(asyncValidationIsFinishedPromise);
+
+                        return;
+                    }
+
+                    const validationResult = validatedSubValues.every((isValid: boolean) => isValid);
+                    if (!validationResult) {
+                        const [type, message] = this.createValidationError(object, value, metadata, customConstraintMetadata);
+                        errorMap[type] = message;
                     }
                 });
         });

Diff for: test/functional/validation-options.spec.ts

@@ -1,9 +1,9 @@
 import "es6-shim";
-import {Contains, Matches, MinLength, ValidateNested} from "../../src/decorator/decorators";
+import {Contains, Matches, MinLength, ValidateNested, ValidatorConstraint, Validate } from "../../src/decorator/decorators";
 import {Validator} from "../../src/validation/Validator";
-import {ValidationError} from "../../src";
+import {ValidationError, ValidatorConstraintInterface} from "../../src";
 
-import {should, use } from "chai";
+import {should, use} from "chai";
 
 import * as chaiAsPromised from "chai-as-promised";
 
@@ -163,6 +163,110 @@ describe("validation options", function() {
             });
         });
 
+        it("should apply validation via custom constraint class to array items (but not array itself)", function() {
+            @ValidatorConstraint({ name: "customIsNotArrayConstraint", async: false })
+            class CustomIsNotArrayConstraint implements ValidatorConstraintInterface {
+                validate(value: any) {
+                    return !(value instanceof Array);
+                }
+            }
+
+            class MyClass {
+                @Validate(CustomIsNotArrayConstraint, {
+                    each: true
+                })
+                someArrayOfNonArrayItems: string[];
+            }
+
+            const model = new MyClass();
+            model.someArrayOfNonArrayItems = ["not array", "also not array", "not array at all"];
+            return validator.validate(model).then(errors => {
+                errors.length.should.be.equal(0);
+            });
+        });
+
+        it("should apply validation via custom constraint class with synchronous logic to each item in the array", function() {
+            @ValidatorConstraint({ name: "customContainsHelloConstraint", async: false })
+            class CustomContainsHelloConstraint implements ValidatorConstraintInterface {
+                validate(value: any) {
+                    return !(value instanceof Array) && String(value).includes("hello");
+                }
+            }
+
+            class MyClass {
+                @Validate(CustomContainsHelloConstraint, {
+                    each: true
+                })
+                someProperty: string[];
+            }
+
+            const model = new MyClass();
+            model.someProperty = ["hell no world", "hello", "helo world", "hello world", "hello dear friend"];
+            return validator.validate(model).then(errors => {
+                errors.length.should.be.equal(1);
+                errors[0].constraints.should.be.eql({ customContainsHelloConstraint: "" });
+                errors[0].value.should.be.equal(model.someProperty);
+                errors[0].target.should.be.equal(model);
+                errors[0].property.should.be.equal("someProperty");
+            });
+        });
+
+        it("should apply validation via custom constraint class with async logic to each item in the array", function() {
+            @ValidatorConstraint({ name: "customAsyncContainsHelloConstraint", async: true })
+            class CustomAsyncContainsHelloConstraint implements ValidatorConstraintInterface {
+                validate(value: any) {
+                    const isValid = !(value instanceof Array) && String(value).includes("hello");
+
+                    return Promise.resolve(isValid);
+                }
+            }
+
+            class MyClass {
+                @Validate(CustomAsyncContainsHelloConstraint, {
+                    each: true
+                })
+                someProperty: string[];
+            }
+
+            const model = new MyClass();
+            model.someProperty = ["hell no world", "hello", "helo world", "hello world", "hello dear friend"];
+            return validator.validate(model).then(errors => {
+                errors.length.should.be.equal(1);
+                errors[0].constraints.should.be.eql({ customAsyncContainsHelloConstraint: "" });
+                errors[0].value.should.be.equal(model.someProperty);
+                errors[0].target.should.be.equal(model);
+                errors[0].property.should.be.equal("someProperty");
+            });
+        });
+
+        it("should apply validation via custom constraint class with mixed (synchronous + async) logic to each item in the array", function() {
+            @ValidatorConstraint({ name: "customMixedContainsHelloConstraint", async: true })
+            class CustomMixedContainsHelloConstraint implements ValidatorConstraintInterface {
+                validate(value: any) {
+                    const isValid = !(value instanceof Array) && String(value).includes("hello");
+
+                    return isValid ? isValid : Promise.resolve(isValid);
+                }
+            }
+
+            class MyClass {
+                @Validate(CustomMixedContainsHelloConstraint, {
+                    each: true
+                })
+                someProperty: string[];
+            }
+
+            const model = new MyClass();
+            model.someProperty = ["hell no world", "hello", "helo world", "hello world", "hello dear friend"];
+            return validator.validate(model).then(errors => {
+                errors.length.should.be.equal(1);
+                errors[0].constraints.should.be.eql({ customMixedContainsHelloConstraint: "" });
+                errors[0].value.should.be.equal(model.someProperty);
+                errors[0].target.should.be.equal(model);
+                errors[0].property.should.be.equal("someProperty");
+            });
+        });
+
     });
 
     describe("groups", function() {