➕ isDataURI

README.md

@@ -17,7 +17,7 @@ Validate is a standard Deno module for validating string.
 * [x] isByteLength
 * [x] isCreditCard
 * [x] isCurrency
-* [ ] isDataURI
+* [x] isDataURI
 * [ ] isDate
 * [ ] isDecimal
 * [ ] isDivisibleBy

src/libs/isDataURI.ts

@@ -0,0 +1,40 @@
+// @ts-ignore allowing typedoc to build
+import assertString from '../utils/assertString.ts';
+
+const validMediaType = /^[a-z]+\/[a-z0-9\-\+]+$/i;
+const validAttribute = /^[a-z\-]+=[a-z0-9\-]+$/i;
+const validData = /^[a-z0-9!\$&'\(\)\*\+,;=\-\._~:@\/\?%\s]*$/i;
+
+export const isDataURI = (str: string) => {
+  assertString(str);
+  let data = str.split(',');
+  if (data.length < 2) {
+    return false;
+  }
+  const attributes = (data.shift() as string).trim().split(';');
+  const schemeAndMediaType = attributes.shift() as string;
+  if (schemeAndMediaType.substr(0, 5) !== 'data:') {
+    return false;
+  }
+  const mediaType = schemeAndMediaType.substr(5);
+  if (mediaType !== '' && !validMediaType.test(mediaType)) {
+    return false;
+  }
+  for (let i = 0; i < attributes.length; i++) {
+    if (
+      i === attributes.length - 1 &&
+      attributes[i].toLowerCase() === 'base64'
+    ) {
+      // ok
+    } else if (!validAttribute.test(attributes[i])) {
+      return false;
+    }
+  }
+  for (let i = 0; i < data.length; i++) {
+    if (!validData.test(data[i])) {
+      return false;
+    }
+  }
+
+  return true;
+};

src/mod.ts

@@ -24,3 +24,5 @@ export * from './libs/isByteLength.ts';
 export * from './libs/isCreditCard.ts';
 // @ts-ignore allowing typedoc to build
 export * from './libs/isCurrency.ts';
+// @ts-ignore allowing typedoc to build
+export * from './libs/isDataURI.ts';