Add support for ES modules

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## v3.1.0
+- Add support for ES modules.
+
 ## v3.0.0
 - Add typings for TypeScript.
 - Drop support for old Node.js < 10.

dist/index.esm.js

@@ -0,0 +1,79 @@
+/*
+    https://tools.ietf.org/html/rfc3629
+
+    UTF8-char = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
+
+    UTF8-1    = %x00-7F
+
+    UTF8-2    = %xC2-DF UTF8-tail
+
+    UTF8-3    = %xE0 %xA0-BF UTF8-tail
+                %xE1-EC 2( UTF8-tail )
+                %xED %x80-9F UTF8-tail
+                %xEE-EF 2( UTF8-tail )
+
+    UTF8-4    = %xF0 %x90-BF 2( UTF8-tail )
+                %xF1-F3 3( UTF8-tail )
+                %xF4 %x80-8F 2( UTF8-tail )
+
+    UTF8-tail = %x80-BF
+*/
+/**
+ * Check if a Node.js Buffer or Uint8Array is UTF-8.
+ */
+function isUtf8(buf) {
+    if (!buf) {
+        return false;
+    }
+    let i = 0;
+    const len = buf.length;
+    while (i < len) {
+        // UTF8-1 = %x00-7F
+        if (buf[i] <= 0x7F) {
+            i++;
+            continue;
+        }
+        // UTF8-2 = %xC2-DF UTF8-tail
+        if (buf[i] >= 0xC2 && buf[i] <= 0xDF) {
+            // if(buf[i + 1] >= 0x80 && buf[i + 1] <= 0xBF) {
+            if (buf[i + 1] >> 6 === 2) {
+                i += 2;
+                continue;
+            }
+            else {
+                return false;
+            }
+        }
+        // UTF8-3 = %xE0 %xA0-BF UTF8-tail
+        // UTF8-3 = %xED %x80-9F UTF8-tail
+        if (((buf[i] === 0xE0 && buf[i + 1] >= 0xA0 && buf[i + 1] <= 0xBF) ||
+            (buf[i] === 0xED && buf[i + 1] >= 0x80 && buf[i + 1] <= 0x9F)) && buf[i + 2] >> 6 === 2) {
+            i += 3;
+            continue;
+        }
+        // UTF8-3 = %xE1-EC 2( UTF8-tail )
+        // UTF8-3 = %xEE-EF 2( UTF8-tail )
+        if (((buf[i] >= 0xE1 && buf[i] <= 0xEC) ||
+            (buf[i] >= 0xEE && buf[i] <= 0xEF)) &&
+            buf[i + 1] >> 6 === 2 &&
+            buf[i + 2] >> 6 === 2) {
+            i += 3;
+            continue;
+        }
+        // UTF8-4 = %xF0 %x90-BF 2( UTF8-tail )
+        //          %xF1-F3 3( UTF8-tail )
+        //          %xF4 %x80-8F 2( UTF8-tail )
+        if (((buf[i] === 0xF0 && buf[i + 1] >= 0x90 && buf[i + 1] <= 0xBF) ||
+            (buf[i] >= 0xF1 && buf[i] <= 0xF3 && buf[i + 1] >> 6 === 2) ||
+            (buf[i] === 0xF4 && buf[i + 1] >= 0x80 && buf[i + 1] <= 0x8F)) &&
+            buf[i + 2] >> 6 === 2 &&
+            buf[i + 3] >> 6 === 2) {
+            i += 4;
+            continue;
+        }
+        return false;
+    }
+    return true;
+}
+
+export default isUtf8;

lib/index.js → dist/index.js

@@ -1,4 +1,5 @@
-"use strict";
+'use strict';
+
 /*
     https://tools.ietf.org/html/rfc3629
 
@@ -19,7 +20,6 @@
 
     UTF8-tail = %x80-BF
 */
-Object.defineProperty(exports, "__esModule", { value: true });
 /**
  * Check if a Node.js Buffer or Uint8Array is UTF-8.
  */
@@ -77,4 +77,5 @@ function isUtf8(buf) {
     }
     return true;
 }
-exports.default = isUtf8;
+
+module.exports = isUtf8;