Initial commit

tests/Unit/BufferTest.php

@@ -0,0 +1,72 @@
+<?php
+
+use Shufflingpixels\IO\Buffer;
+use Shufflingpixels\IO\Exception\EndOfStreamException;
+use Shufflingpixels\IO\SeekMode;
+
+it('reads, seeks and tracks position', function () {
+    $buffer = new Buffer('abcdef');
+
+    expect($buffer->length())->toBe(6)
+        ->and($buffer->tell())->toBe(0)
+        ->and($buffer->remaining())->toBe(6)
+        ->and($buffer->eof())->toBeFalse();
+
+    expect($buffer->read(2))->toBe('ab')
+        ->and($buffer->tell())->toBe(2)
+        ->and($buffer->remaining())->toBe(4);
+
+    $buffer->seek(-1, SeekMode::END);
+
+    expect($buffer->tell())->toBe(5)
+        ->and($buffer->read(1))->toBe('f')
+        ->and($buffer->eof())->toBeTrue();
+});
+
+it('supports relative seek modes', function () {
+    $buffer = new Buffer('abcdef');
+
+    $buffer->seek(3);
+    $buffer->seek(-2, SeekMode::CUR);
+
+    expect($buffer->tell())->toBe(1)
+        ->and($buffer->read(2))->toBe('bc');
+});
+
+it('throws for out of bounds seek', function () {
+    $buffer = new Buffer('abc');
+
+    expect(fn () => $buffer->seek(4))->toThrow(OutOfBoundsException::class);
+});
+
+it('throws for negative read length', function () {
+    $buffer = new Buffer('abc');
+
+    expect(fn () => $buffer->read(-1))->toThrow(InvalidArgumentException::class);
+});
+
+it('throws when reading beyond end of stream', function () {
+    $buffer = new Buffer('abc');
+
+    expect(fn () => $buffer->read(4))->toThrow(EndOfStreamException::class);
+});
+
+it('writes at current position and updates contents', function () {
+    $buffer = new Buffer('abcdef');
+    $buffer->seek(2);
+
+    expect($buffer->write('XY'))->toBe(2)
+        ->and($buffer->tell())->toBe(4);
+
+    $buffer->seek(0);
+
+    expect($buffer->read(6))->toBe('abXYef');
+});
+
+it('writes nothing for empty payload', function () {
+    $buffer = new Buffer('abc');
+
+    expect($buffer->write(''))->toBe(0)
+        ->and($buffer->tell())->toBe(0)
+        ->and($buffer->length())->toBe(3);
+});