feat: decode text

Author: santi-mir

src/IOBuffer.ts

@@ -1,4 +1,4 @@
-import { decode, encode } from './utf8';
+import { decode, encode } from './text';
 
 const defaultByteLength = 1024 * 8;
 
@@ -366,6 +366,15 @@ export class IOBuffer {
     return decode(this.readBytes(n));
   }
 
+  /**
+   * Read the next `n` bytes, return a string decoded with `encoding` and move pointer
+   * forward by `n` bytes.
+   * If no encoding is passed, the function is equivalent to @see {@link IOBuffer#readUtf8}
+   */
+  public decodeText(n = 1, encoding = 'utf-8'): string {
+    return decode(this.readBytes(n), encoding);
+  }
+
   /**
    * Write 0xff if the passed value is truthy, 0x00 otherwise and move pointer
    * forward by 1 byte.

src/__tests__/read.ts

@@ -114,4 +114,21 @@ describe('read data', () => {
     theBuffer.seek(1);
     expect(theBuffer.readUtf8()).toBe('4');
   });
+
+  it('decodeText', () => {
+    const theBuffer = new IOBuffer(
+      Buffer.from([
+        42, 0x34, 0x32, 0xe2, 0x82, 0xac, 42, 0x72, 0x75, 0x6e, 0x21, 0xcf,
+        0x79, 0x6f, 0x73, 0x65, 0x6d, 0x69, 0x74, 0x65,
+      ]),
+    );
+    expect(theBuffer.readByte()).toBe(42);
+    const strE1 = theBuffer.decodeText(5);
+    expect(strE1).toBe('42€');
+    expect(theBuffer.readByte()).toBe(42);
+    const strE2 = theBuffer.decodeText(4, 'windows-1251');
+    expect(strE2).toBe('run!');
+    expect(theBuffer.decodeText(1, 'windows-1251')).toBe('П');
+    expect(theBuffer.decodeText(8, 'ISO-8859-2')).toBe('yosemite');
+  });
 });

src/utf8.browser.ts src/text.browser.tssrc/utf8.browser.ts renamed to src/text.browser.ts

@@ -1,9 +1,8 @@
 // eslint-disable-next-line import/no-unassigned-import
 import './text-encoding-polyfill';
 
-const decoder = new TextDecoder('utf-8');
-
-export function decode(bytes: Uint8Array): string {
+export function decode(bytes: Uint8Array, encoding = 'utf8'): string {
+  const decoder = new TextDecoder(encoding);
   return decoder.decode(bytes);
 }
 

src/utf8.ts src/text.tssrc/utf8.ts renamed to src/text.ts

@@ -1,8 +1,7 @@
 import { TextDecoder, TextEncoder } from 'util';
 
-const decoder = new TextDecoder('utf-8');
-
-export function decode(bytes: Uint8Array): string {
+export function decode(bytes: Uint8Array, encoding = 'utf8'): string {
+  const decoder = new TextDecoder(encoding);
   return decoder.decode(bytes);
 }