stream: adopt PSR-7 StreamInterface

tests/Unit/BufferTest.php

@@ -1,13 +1,11 @@
 <?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($buffer->length())->toBe(6)
+    expect($buffer->getSize())->toBe(6)
         ->and($buffer->tell())->toBe(0)
         ->and($buffer->remaining())->toBe(6)
         ->and($buffer->eof())->toBeFalse();
@@ -16,7 +14,7 @@ it('reads, seeks and tracks position', function () {
         ->and($buffer->tell())->toBe(2)
         ->and($buffer->remaining())->toBe(4);
 
-    $buffer->seek(-1, SeekMode::END);
+    $buffer->seek(-1, SEEK_END);
 
     expect($buffer->tell())->toBe(5)
         ->and($buffer->read(1))->toBe('f')
@@ -27,7 +25,7 @@ it('supports relative seek modes', function () {
     $buffer = new Buffer('abcdef');
 
     $buffer->seek(3);
-    $buffer->seek(-2, SeekMode::CUR);
+    $buffer->seek(-2, SEEK_CUR);
 
     expect($buffer->tell())->toBe(1)
         ->and($buffer->read(2))->toBe('bc');
@@ -45,10 +43,11 @@ it('throws for negative read length', function () {
     expect(fn () => $buffer->read(-1))->toThrow(InvalidArgumentException::class);
 });
 
-it('throws when reading beyond end of stream', function () {
+it('returns available bytes when reading beyond end of stream', function () {
     $buffer = new Buffer('abc');
 
-    expect(fn () => $buffer->read(4))->toThrow(EndOfStreamException::class);
+    expect($buffer->read(4))->toBe('abc')
+        ->and($buffer->eof())->toBeTrue();
 });
 
 it('writes at current position and updates contents', function () {
@@ -68,5 +67,14 @@ it('writes nothing for empty payload', function () {
 
     expect($buffer->write(''))->toBe(0)
         ->and($buffer->tell())->toBe(0)
-        ->and($buffer->length())->toBe(3);
+        ->and($buffer->getSize())->toBe(3);
+});
+
+it('returns remaining contents and advances cursor', function () {
+    $buffer = new Buffer('abcdef');
+    $buffer->seek(2);
+
+    expect($buffer->getContents())->toBe('cdef')
+        ->and($buffer->tell())->toBe(6)
+        ->and($buffer->getContents())->toBe('');
 });