From 5b5dc8fbb872017b9e902c697a296ca9c2371fe7 Mon Sep 17 00:00:00 2001
From: Vahn Gomes <me@vahngomes.dev>
Date: Mon, 8 Jan 2024 15:25:31 -0500
Subject: [PATCH] feat(validator): add enum validation to Validator class to
 support enum type fields

---
 __tests__/validator.test.ts | 42 +++++++++++++++++++++++++++++++++++++
 src/index.ts                | 20 +++++++++++++++++-
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/__tests__/validator.test.ts b/__tests__/validator.test.ts
index 434e350..e07c6d3 100644
--- a/__tests__/validator.test.ts
+++ b/__tests__/validator.test.ts
@@ -556,3 +556,45 @@ describe("Validator - Specific Types", () => {
     expect(validator.getErrors().date).toBe("Expected a date");
   });
 });
+
+describe("Validator - Enum", () => {
+  it("should throw when given a value not in the enum", () => {
+    const validator = new Validator(
+      { status: { enum: ["active", "inactive"] } },
+      { status: { enum: "Expected a value in the enum" } }
+    );
+    expect(validator.validate({ status: "deleted" })).resolves.toBe(false);
+    expect(validator.getErrors().status).toBe("Expected a value in the enum");
+  });
+
+  it("should not throw when given a value in the enum", () => {
+    const validator = new Validator(
+      { status: { enum: ["active", "inactive"] } },
+      { status: { enum: "Expected a value in the enum" } }
+    );
+    expect(validator.validate({ status: "active" })).resolves.toBe(true);
+    expect(validator.getErrors().status).toBeUndefined();
+  });
+});
+
+describe("Validator - Input", () => {
+  it("should throw when given a non-object", () => {
+    const validator = new Validator(
+      { name: { type: "string" } },
+      { name: { type: "Expected a string" } }
+    );
+    expect(validator.validate("John Doe")).rejects.toThrow(
+      "Input must be an object"
+    );
+  });
+
+  it("should throw when given a array", () => {
+    const validator = new Validator(
+      { name: { type: "string" } },
+      { name: { type: "Expected a string" } }
+    );
+    expect(validator.validate(["John Doe"])).rejects.toThrow(
+      "Input must be an object"
+    );
+  });
+});
diff --git a/src/index.ts b/src/index.ts
index a568b9b..59b1328 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -38,6 +38,10 @@ interface Rule {
    * Regular expression to validate the field.
    */
   regex?: RegExp;
+  /**
+   * Enumeration of valid values.
+   */
+  enum?: Array<string | number | boolean>;
 }
 
 /**
@@ -76,6 +80,10 @@ interface Message {
    * The error message for regex validation failure.
    */
   regex?: string;
+  /**
+   * The error message for invalid enum value.
+   */
+  enum?: string;
 }
 
 /**
@@ -363,6 +371,16 @@ class Validator {
           isValid = false;
         }
       }
+
+      // Enumeration validation
+      if (rule.enum && !rule.enum.includes(value)) {
+        this.errors[key] =
+          this.messages[key].enum ??
+          `"${key}" must be one of the following values: ${rule.enum.join(
+            ", "
+          )}.`;
+        isValid = false;
+      }
     }
 
     // If strict mode is enabled, check for fields that are not defined in rules
@@ -447,4 +465,4 @@ export type {
 };
 
 // Export class
-export default Validator;
\ No newline at end of file
+export default Validator;