Add base64 string validation

colinhacks · Dec 12, 2023 · 96f6f5d · 96f6f5d
1 parent 0e89027
commit 96f6f5d
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Showing 8 changed files with 114 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -747,6 +747,7 @@ z.string().startsWith(string);
 z.string().endsWith(string);
 z.string().datetime(); // ISO 8601; default is without UTC offset, see below for options
 z.string().ip(); // defaults to IPv4 and IPv6, see below for options
+z.string().base64();
 
 // transformations
 z.string().trim(); // trim whitespace

diff --git a/deno/lib/README.md b/deno/lib/README.md
@@ -747,6 +747,7 @@ z.string().startsWith(string);
 z.string().endsWith(string);
 z.string().datetime(); // ISO 8601; default is without UTC offset, see below for options
 z.string().ip(); // defaults to IPv4 and IPv6, see below for options
+z.string().base64();
 
 // transformations
 z.string().trim(); // trim whitespace

diff --git a/deno/lib/ZodError.ts b/deno/lib/ZodError.ts
@@ -99,6 +99,7 @@ export type StringValidation =
   | "ulid"
   | "datetime"
   | "ip"
+  | "base64"
   | { includes: string; position?: number }
   | { startsWith: string }
   | { endsWith: string };

diff --git a/deno/lib/__tests__/string.test.ts b/deno/lib/__tests__/string.test.ts
@@ -162,6 +162,39 @@ test("email validations", () => {
   ).toBe(true);
 });
 
+test("base64 validations", () => {
+  const validBase64Strings = [
+      "SGVsbG8gV29ybGQ=", // "Hello World"
+      "VGhpcyBpcyBhbiBlbmNvZGVkIHN0cmluZw==", // "This is an encoded string"
+      "TWFueSBoYW5kcyBtYWtlIGxpZ2h0IHdvcms=", // "Many hands make light work"
+      "UGF0aWVuY2UgaXMgdGhlIGtleSB0byBzdWNjZXNz", // "Patience is the key to success"
+      "QmFzZTY0IGVuY29kaW5nIGlzIGZ1bg==", // "Base64 encoding is fun"
+      "MTIzNDU2Nzg5MA==", // "1234567890"
+      "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXo=", // "abcdefghijklmnopqrstuvwxyz"
+      "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVo=", // "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+      "ISIkJSMmJyonKCk=", // "!\"#$%&'()*"
+      "" // Empty string is technically a valid base64
+  ];
+
+  for (const str of validBase64Strings) {
+    expect(str + z.string().base64().safeParse(str).success).toBe(str + "true");
+  }
+
+  const invalidBase64Strings = [
+      "12345", // Not padded correctly, not a multiple of 4 characters
+      "SGVsbG8gV29ybGQ", // Missing padding
+      "VGhpcyBpcyBhbiBlbmNvZGVkIHN0cmluZw", // Missing padding
+      "!UGF0aWVuY2UgaXMgdGhlIGtleSB0byBzdWNjZXNz", // Invalid character '!'
+      "?QmFzZTY0IGVuY29kaW5nIGlzIGZ1bg==", // Invalid character '?'
+      ".MTIzND2Nzg5MC4=", // Invalid character '.'
+      "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVo", // Missing padding
+  ];
+
+  for (const str of invalidBase64Strings) {
+    expect(str + z.string().base64().safeParse(str).success).toBe(str + "false");
+  }
+})
+
 test("url validations", () => {
   const url = z.string().url();
   url.parse("http://google.com");

diff --git a/deno/lib/types.ts b/deno/lib/types.ts
@@ -537,7 +537,8 @@ export type ZodStringCheck =
       precision: number | null;
       message?: string;
     }
-  | { kind: "ip"; version?: IpVersion; message?: string };
+  | { kind: "ip"; version?: IpVersion; message?: string }
+  | { kind: "base64"; message?: string };
 
 export interface ZodStringDef extends ZodTypeDef {
   checks: ZodStringCheck[];
@@ -579,6 +580,10 @@ const ipv4Regex =
 const ipv6Regex =
   /^(([a-f0-9]{1,4}:){7}|::([a-f0-9]{1,4}:){0,6}|([a-f0-9]{1,4}:){1}:([a-f0-9]{1,4}:){0,5}|([a-f0-9]{1,4}:){2}:([a-f0-9]{1,4}:){0,4}|([a-f0-9]{1,4}:){3}:([a-f0-9]{1,4}:){0,3}|([a-f0-9]{1,4}:){4}:([a-f0-9]{1,4}:){0,2}|([a-f0-9]{1,4}:){5}:([a-f0-9]{1,4}:){0,1})([a-f0-9]{1,4}|(((25[0-5])|(2[0-4][0-9])|(1[0-9]{2})|([0-9]{1,2}))\.){3}((25[0-5])|(2[0-4][0-9])|(1[0-9]{2})|([0-9]{1,2})))$/;
 
+// https://stackoverflow.com/questions/7860392/determine-if-string-is-in-base64-using-javascript
+const base64Regex =
+  /^([0-9a-zA-Z+/]{4})*(([0-9a-zA-Z+/]{2}==)|([0-9a-zA-Z+/]{3}=))?$/;
+
 // Adapted from https://stackoverflow.com/a/3143231
 const datetimeRegex = (args: { precision: number | null; offset: boolean }) => {
   if (args.precision) {
@@ -845,6 +850,16 @@ export class ZodString extends ZodType<string, ZodStringDef> {
           });
           status.dirty();
         }
+      } else if (check.kind === "base64") {
+        if (!base64Regex.test(input.data)) {
+          ctx = this._getOrReturnCtx(input, ctx);
+          addIssueToContext(ctx, {
+            validation: "base64",
+            code: ZodIssueCode.invalid_string,
+            message: check.message,
+          });
+          status.dirty();
+        }
       } else {
         util.assertNever(check);
       }
@@ -893,6 +908,9 @@ export class ZodString extends ZodType<string, ZodStringDef> {
   ulid(message?: errorUtil.ErrMessage) {
     return this._addCheck({ kind: "ulid", ...errorUtil.errToObj(message) });
   }
+  base64(message?: errorUtil.ErrMessage) {
+    return this._addCheck({ kind: "base64", ...errorUtil.errToObj(message) });
+  }
 
   ip(options?: string | { version?: "v4" | "v6"; message?: string }) {
     return this._addCheck({ kind: "ip", ...errorUtil.errToObj(options) });
@@ -1038,6 +1056,9 @@ export class ZodString extends ZodType<string, ZodStringDef> {
   get isIP() {
     return !!this._def.checks.find((ch) => ch.kind === "ip");
   }
+  get isBase64() {
+    return !!this._def.checks.find((ch) => ch.kind === "base64");
+  }
 
   get minLength() {
     let min: number | null = null;

diff --git a/src/ZodError.ts b/src/ZodError.ts
@@ -99,6 +99,7 @@ export type StringValidation =
   | "ulid"
   | "datetime"
   | "ip"
+  | "base64"
   | { includes: string; position?: number }
   | { startsWith: string }
   | { endsWith: string };

diff --git a/src/__tests__/string.test.ts b/src/__tests__/string.test.ts
@@ -161,6 +161,39 @@ test("email validations", () => {
   ).toBe(true);
 });
 
+test("base64 validations", () => {
+  const validBase64Strings = [
+      "SGVsbG8gV29ybGQ=", // "Hello World"
+      "VGhpcyBpcyBhbiBlbmNvZGVkIHN0cmluZw==", // "This is an encoded string"
+      "TWFueSBoYW5kcyBtYWtlIGxpZ2h0IHdvcms=", // "Many hands make light work"
+      "UGF0aWVuY2UgaXMgdGhlIGtleSB0byBzdWNjZXNz", // "Patience is the key to success"
+      "QmFzZTY0IGVuY29kaW5nIGlzIGZ1bg==", // "Base64 encoding is fun"
+      "MTIzNDU2Nzg5MA==", // "1234567890"
+      "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXo=", // "abcdefghijklmnopqrstuvwxyz"
+      "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVo=", // "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+      "ISIkJSMmJyonKCk=", // "!\"#$%&'()*"
+      "" // Empty string is technically a valid base64
+  ];
+
+  for (const str of validBase64Strings) {
+    expect(str + z.string().base64().safeParse(str).success).toBe(str + "true");
+  }
+
+  const invalidBase64Strings = [
+      "12345", // Not padded correctly, not a multiple of 4 characters
+      "SGVsbG8gV29ybGQ", // Missing padding
+      "VGhpcyBpcyBhbiBlbmNvZGVkIHN0cmluZw", // Missing padding
+      "!UGF0aWVuY2UgaXMgdGhlIGtleSB0byBzdWNjZXNz", // Invalid character '!'
+      "?QmFzZTY0IGVuY29kaW5nIGlzIGZ1bg==", // Invalid character '?'
+      ".MTIzND2Nzg5MC4=", // Invalid character '.'
+      "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVo", // Missing padding
+  ];
+
+  for (const str of invalidBase64Strings) {
+    expect(str + z.string().base64().safeParse(str).success).toBe(str + "false");
+  }
+})
+
 test("url validations", () => {
   const url = z.string().url();
   url.parse("http://google.com");

diff --git a/src/types.ts b/src/types.ts
@@ -537,7 +537,8 @@ export type ZodStringCheck =
       precision: number | null;
       message?: string;
     }
-  | { kind: "ip"; version?: IpVersion; message?: string };
+  | { kind: "ip"; version?: IpVersion; message?: string }
+  | { kind: "base64"; message?: string };
 
 export interface ZodStringDef extends ZodTypeDef {
   checks: ZodStringCheck[];
@@ -579,6 +580,10 @@ const ipv4Regex =
 const ipv6Regex =
   /^(([a-f0-9]{1,4}:){7}|::([a-f0-9]{1,4}:){0,6}|([a-f0-9]{1,4}:){1}:([a-f0-9]{1,4}:){0,5}|([a-f0-9]{1,4}:){2}:([a-f0-9]{1,4}:){0,4}|([a-f0-9]{1,4}:){3}:([a-f0-9]{1,4}:){0,3}|([a-f0-9]{1,4}:){4}:([a-f0-9]{1,4}:){0,2}|([a-f0-9]{1,4}:){5}:([a-f0-9]{1,4}:){0,1})([a-f0-9]{1,4}|(((25[0-5])|(2[0-4][0-9])|(1[0-9]{2})|([0-9]{1,2}))\.){3}((25[0-5])|(2[0-4][0-9])|(1[0-9]{2})|([0-9]{1,2})))$/;
 
+// https://stackoverflow.com/questions/7860392/determine-if-string-is-in-base64-using-javascript
+const base64Regex =
+  /^([0-9a-zA-Z+/]{4})*(([0-9a-zA-Z+/]{2}==)|([0-9a-zA-Z+/]{3}=))?$/;
+
 // Adapted from https://stackoverflow.com/a/3143231
 const datetimeRegex = (args: { precision: number | null; offset: boolean }) => {
   if (args.precision) {
@@ -845,6 +850,16 @@ export class ZodString extends ZodType<string, ZodStringDef> {
           });
           status.dirty();
         }
+      } else if (check.kind === "base64") {
+        if (!base64Regex.test(input.data)) {
+          ctx = this._getOrReturnCtx(input, ctx);
+          addIssueToContext(ctx, {
+            validation: "base64",
+            code: ZodIssueCode.invalid_string,
+            message: check.message,
+          });
+          status.dirty();
+        }
       } else {
         util.assertNever(check);
       }
@@ -893,6 +908,9 @@ export class ZodString extends ZodType<string, ZodStringDef> {
   ulid(message?: errorUtil.ErrMessage) {
     return this._addCheck({ kind: "ulid", ...errorUtil.errToObj(message) });
   }
+  base64(message?: errorUtil.ErrMessage) {
+    return this._addCheck({ kind: "base64", ...errorUtil.errToObj(message) });
+  }
 
   ip(options?: string | { version?: "v4" | "v6"; message?: string }) {
     return this._addCheck({ kind: "ip", ...errorUtil.errToObj(options) });
@@ -1038,6 +1056,9 @@ export class ZodString extends ZodType<string, ZodStringDef> {
   get isIP() {
     return !!this._def.checks.find((ch) => ch.kind === "ip");
   }
+  get isBase64() {
+    return !!this._def.checks.find((ch) => ch.kind === "base64");
+  }
 
   get minLength() {
     let min: number | null = null;