test: add more ID3 tests

see: streaming-video-technology-alliance#74

---------

Signed-off-by: Felipe Young <[email protected]>
Co-authored-by: Fernando Cuadro <[email protected]>
Signed-off-by: Casey Occhialini <[email protected]>

CHANGELOG.md

@@ -18,6 +18,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Unit tests for id3 feature helper functions [#74](https://github.com/streaming-video-technology-alliance/common-media-library/pull/74)
+
 
 ## [0.6.2] - 2023-01-18
 

lib/src/id3/getId3Frames.ts

@@ -6,6 +6,9 @@ import { isId3Footer } from './util/isId3Footer.js';
 import { isId3Header } from './util/isId3Header.js';
 import { readId3Size } from './util/readId3Size.js';
 
+const HEADER_FOOTER_SIZE = 10;
+const FRAME_SIZE = 10;
+
 /**
  * Returns an array of ID3 frames found in all the ID3 tags in the id3Data
  *
@@ -24,10 +27,10 @@ export function getId3Frames(id3Data: Uint8Array): Id3Frame[] {
 	while (isId3Header(id3Data, offset)) {
 		const size = readId3Size(id3Data, offset + 6);
 		// skip past ID3 header
-		offset += 10;
+		offset += HEADER_FOOTER_SIZE;
 		const end = offset + size;
 		// loop through frames in the ID3 tag
-		while (offset + 8 < end) {
+		while (offset + FRAME_SIZE < end) {
 			const frameData: RawId3Frame = getId3FrameData(id3Data.subarray(offset));
 			const frame: Id3Frame | undefined = decodeId3Frame(frameData);
 			if (frame) {
@@ -39,7 +42,7 @@ export function getId3Frames(id3Data: Uint8Array): Id3Frame[] {
 		}
 
 		if (isId3Footer(id3Data, offset)) {
-			offset += 10;
+			offset += HEADER_FOOTER_SIZE;
 		}
 	}
 

lib/test/id3/decodeId3TextFrame.test.ts

@@ -0,0 +1,23 @@
+import { equal } from 'node:assert';
+import { describe, it } from 'node:test';
+import { decodeId3TextFrame } from '../../src/id3/util/decodeId3TextFrame.js';
+import { Id3Frame } from '../../src/id3';
+
+describe('decodeId3TextFrame', () => {
+	it('should decode a TXXX frame', () => {
+		const frame = {
+			type: 'TXXX',
+			data: new Uint8Array([0, 102, 111, 111, 0, 97, 98, 99]),
+			size: 2, // required by the decodeTextFrame function
+		};
+
+		const testables = {
+			decodeId3TextFrame: decodeId3TextFrame,
+		};
+
+		const result: Id3Frame | undefined = testables.decodeId3TextFrame(frame);
+		equal(result!.key, 'TXXX');
+		equal(result!.info, 'foo');
+		equal(result!.data, 'abc');
+	});
+});

lib/test/id3/isId3Footer.test.ts

@@ -0,0 +1,30 @@
+import { equal } from 'node:assert';
+import { describe, it } from 'node:test';
+import { isId3Footer } from '../../src/id3/util/isId3Footer.js';
+
+const LEADING_BYTE_SIZE = 8;
+const TRAILING_BYTE_SIZE = 8;
+
+describe('isId3Footer', () => {
+	const mockID3Footer = Uint8Array.from([
+		0x33, 0x44, 0x49, 4, 0, 0, 0, 0, 0, 63, 80, 82, 73, 86, 0, 0, 0, 53, 0, 0,
+		99, 111, 109, 46, 97, 112, 112, 108, 101, 46, 115, 116, 114, 101, 97, 109,
+		105, 110, 103, 46, 116, 114, 97, 110, 115, 112, 111, 114, 116, 83, 116, 114,
+		101, 97, 109, 84, 105, 109, 101, 115, 116, 97, 109, 112, 0, 0, 0, 0, 0, 0,
+		13, 198, 135,
+	]);
+	const mockID3FooterMissingLeadingByte = mockID3Footer.slice(
+		LEADING_BYTE_SIZE,
+		mockID3Footer.length
+	);
+	const mockID3FooterMissingTrailingByte = mockID3Footer.slice(
+		0,
+		mockID3Footer.length - TRAILING_BYTE_SIZE
+	);
+
+	it('Properly parses ID3 Footers', () => {
+		equal(isId3Footer(mockID3Footer, 0), true);
+		equal(isId3Footer(mockID3FooterMissingLeadingByte, 0), false);
+		equal(isId3Footer(mockID3FooterMissingTrailingByte, 0), true);
+	});
+});

lib/test/id3/isId3Header.test.ts

@@ -0,0 +1,30 @@
+import { equal } from 'node:assert';
+import { describe, it } from 'node:test';
+import { isId3Header } from '../../src/id3/util/isId3Header.js';
+
+const LEADING_BYTE_SIZE = 8;
+const TRAILING_BYTE_SIZE = 8;
+
+describe('isId3Header', () => {
+	const mockID3Header = Uint8Array.from([
+		73, 68, 51, 4, 0, 0, 0, 0, 0, 63, 80, 82, 73, 86, 0, 0, 0, 53, 0, 0, 99,
+		111, 109, 46, 97, 112, 112, 108, 101, 46, 115, 116, 114, 101, 97, 109, 105,
+		110, 103, 46, 116, 114, 97, 110, 115, 112, 111, 114, 116, 83, 116, 114, 101,
+		97, 109, 84, 105, 109, 101, 115, 116, 97, 109, 112, 0, 0, 0, 0, 0, 0, 13,
+		198, 135,
+	]);
+	const mockID3HeaderMissingLeadingByte = mockID3Header.slice(
+		LEADING_BYTE_SIZE,
+		mockID3Header.length
+	);
+	const mockID3HeaderMissingTrailingByte = mockID3Header.slice(
+		0,
+		mockID3Header.length - TRAILING_BYTE_SIZE
+	);
+
+	it('Properly parses ID3 Headers', () => {
+		equal(isId3Header(mockID3Header, 0), true);
+		equal(isId3Header(mockID3HeaderMissingLeadingByte, 0), false);
+		equal(isId3Header(mockID3HeaderMissingTrailingByte, 0), true);
+	});
+});

lib/test/id3/readId3Size.test.ts

@@ -0,0 +1,10 @@
+import { equal } from 'node:assert';
+import { describe, it } from 'node:test';
+import { readId3Size } from '../../src/id3/util/readId3Size.js';
+
+describe('readId3Size', () => {
+	const mockID3SizeData = Uint8Array.from([73, 68, 51, 4, 0, 0, 0, 7, 1, 0]);
+	it('returns Id3 size', () => {
+		equal(readId3Size(mockID3SizeData, 6), 114816);
+	});
+});