White space strings are transformed to undefined on schemas that pars…

…e strings

package.json

@@ -1,6 +1,6 @@
 {
   "name": "not-me",
-  "version": "4.3.6",
+  "version": "4.3.7",
   "description": "Easy and type-safe validation",
   "main": "lib/index.js",
   "types": "lib/types.d.ts",

src/schemas/boolean/boolean-schema.spec.ts

@@ -0,0 +1,22 @@
+import { Schema } from "../schema";
+import { boolean } from "./boolean-schema";
+
+describe("Date Schema", () => {
+  it("Empty strings should be transformed to undefined", () => {
+    const schema: Schema<boolean | undefined | null> = boolean();
+
+    expect(schema.validate("")).toEqual({
+      errors: false,
+      value: undefined,
+    });
+  });
+
+  it("Strings with only whitespaces should be transformed to undefined", () => {
+    const schema: Schema<boolean | undefined | null> = boolean();
+
+    expect(schema.validate("   ")).toEqual({
+      errors: false,
+      value: undefined,
+    });
+  });
+});

src/schemas/boolean/boolean-schema.ts

@@ -30,6 +30,20 @@ class BooleanSchemaImpl<
         };
       }
     });
+
+    this.wrapValueBeforeValidation = (input) => {
+      if (typeof input === "string") {
+        const trimmed = input.trim();
+
+        if (!trimmed) {
+          return undefined;
+        } else {
+          return trimmed;
+        }
+      } else {
+        return input;
+      }
+    };
   }
 
   required(message?: string): BooleanSchemaImpl<boolean> {

src/schemas/date/date-schema.spec.ts

@@ -24,4 +24,22 @@ describe("Date Schema", () => {
       expect(result.value.getTime()).toBe(dateInput.getTime());
     }
   });
+
+  it("Empty strings should be transformed to undefined", () => {
+    const schema: Schema<Date | undefined | null> = date();
+
+    expect(schema.validate("")).toEqual({
+      errors: false,
+      value: undefined,
+    });
+  });
+
+  it("Strings with only whitespaces should be transformed to undefined", () => {
+    const schema: Schema<Date | undefined | null> = date();
+
+    expect(schema.validate("   ")).toEqual({
+      errors: false,
+      value: undefined,
+    });
+  });
 });

src/schemas/date/date-schema.ts

@@ -53,6 +53,20 @@ class DateSchemaImpl<_Output = Date | undefined | null> extends BaseSchema<
         };
       }
     });
+
+    this.wrapValueBeforeValidation = (input) => {
+      if (typeof input === "string") {
+        const trimmed = input.trim();
+
+        if (!trimmed) {
+          return undefined;
+        } else {
+          return trimmed;
+        }
+      } else {
+        return input;
+      }
+    };
   }
 
   required(message?: string): DateSchemaImpl<Date> {

src/schemas/number/number-schema.spec.ts

@@ -38,7 +38,7 @@ describe("Number Schema", () => {
     });
   });
 
-  it("Strings with whitespaces should be transformed to undefined", () => {
+  it("Strings with only whitespaces should be transformed to undefined", () => {
     const schema: Schema<number | undefined | null> = number();
 
     expect(schema.validate("   ")).toEqual({