feat: Allow passing custom message to literal

Fixes #2974

Uses a message key instead of "invalid_xx" key - because those are only used for required and invalid type
using a message key is more in line with other checks

deno/lib/__tests__/literal.test.ts

@@ -5,6 +5,9 @@ const test = Deno.test;
 import * as z from "../index.ts";
 
 const literalTuna = z.literal("tuna");
+const literalTunaCustomMessage = z.literal("tuna", {
+  message: "That's not a tuna",
+});
 const literalFortyTwo = z.literal(42);
 const literalTrue = z.literal(true);
 
@@ -35,3 +38,21 @@ test("invalid_literal should have `received` field with data", () => {
     }
   }
 });
+
+test("invalid_literal should return default message", () => {
+  const data = "shark";
+  const result = literalTuna.safeParse(data);
+  if (!result.success) {
+    const issue = result.error.issues[0];
+    expect(issue.message).toEqual(`Invalid literal value, expected \"tuna\"`);
+  }
+});
+
+test("invalid_literal should return custom message", () => {
+  const data = "shark";
+  const result = literalTunaCustomMessage.safeParse(data);
+  if (!result.success) {
+    const issue = result.error.issues[0];
+    expect(issue.message).toEqual(`That's not a tuna`);
+  }
+});

deno/lib/types.ts

@@ -3913,6 +3913,7 @@ export class ZodLazy<T extends ZodTypeAny> extends ZodType<
 export interface ZodLiteralDef<T = any> extends ZodTypeDef {
   value: T;
   typeName: ZodFirstPartyTypeKind.ZodLiteral;
+  message?: string;
 }
 
 export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
@@ -3923,6 +3924,7 @@ export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
         received: ctx.data,
         code: ZodIssueCode.invalid_literal,
         expected: this._def.value,
+        message: this._def.message,
       });
       return INVALID;
     }
@@ -3935,11 +3937,12 @@ export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
 
   static create = <T extends Primitive>(
     value: T,
-    params?: RawCreateParams
+    params?: RawCreateParams & Exclude<errorUtil.ErrMessage, string>
   ): ZodLiteral<T> => {
     return new ZodLiteral({
       value: value,
       typeName: ZodFirstPartyTypeKind.ZodLiteral,
+      message: params?.message,
       ...processCreateParams(params),
     });
   };

src/__tests__/literal.test.ts

@@ -4,6 +4,9 @@ import { expect, test } from "@jest/globals";
 import * as z from "../index";
 
 const literalTuna = z.literal("tuna");
+const literalTunaCustomMessage = z.literal("tuna", {
+  message: "That's not a tuna",
+});
 const literalFortyTwo = z.literal(42);
 const literalTrue = z.literal(true);
 
@@ -34,3 +37,21 @@ test("invalid_literal should have `received` field with data", () => {
     }
   }
 });
+
+test("invalid_literal should return default message", () => {
+  const data = "shark";
+  const result = literalTuna.safeParse(data);
+  if (!result.success) {
+    const issue = result.error.issues[0];
+    expect(issue.message).toEqual(`Invalid literal value, expected \"tuna\"`);
+  }
+});
+
+test("invalid_literal should return custom message", () => {
+  const data = "shark";
+  const result = literalTunaCustomMessage.safeParse(data);
+  if (!result.success) {
+    const issue = result.error.issues[0];
+    expect(issue.message).toEqual(`That's not a tuna`);
+  }
+});

src/types.ts

@@ -3913,6 +3913,7 @@ export class ZodLazy<T extends ZodTypeAny> extends ZodType<
 export interface ZodLiteralDef<T = any> extends ZodTypeDef {
   value: T;
   typeName: ZodFirstPartyTypeKind.ZodLiteral;
+  message?: string;
 }
 
 export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
@@ -3923,6 +3924,7 @@ export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
         received: ctx.data,
         code: ZodIssueCode.invalid_literal,
         expected: this._def.value,
+        message: this._def.message,
       });
       return INVALID;
     }
@@ -3935,11 +3937,12 @@ export class ZodLiteral<T> extends ZodType<T, ZodLiteralDef<T>> {
 
   static create = <T extends Primitive>(
     value: T,
-    params?: RawCreateParams
+    params?: RawCreateParams & Exclude<errorUtil.ErrMessage, string>
   ): ZodLiteral<T> => {
     return new ZodLiteral({
       value: value,
       typeName: ZodFirstPartyTypeKind.ZodLiteral,
+      message: params?.message,
       ...processCreateParams(params),
     });
   };