test: add file utilities tests

- Add tests for file processing constraints and validators
- Add tests for FileProcessor and FileResolver
- Add tests for resolved file types
- Add tests for file store operations
- Add unit tests for multimodal LLM support

lib/crewai/tests/utilities/files/processing/test_processor.py

@@ -0,0 +1,220 @@
+"""Tests for FileProcessor class."""
+
+import pytest
+
+from crewai.utilities.files import FileBytes, ImageFile, PDFFile, TextFile
+from crewai.utilities.files.processing.constraints import (
+    ANTHROPIC_CONSTRAINTS,
+    ImageConstraints,
+    PDFConstraints,
+    ProviderConstraints,
+)
+from crewai.utilities.files.processing.enums import FileHandling
+from crewai.utilities.files.processing.exceptions import (
+    FileTooLargeError,
+    FileValidationError,
+)
+from crewai.utilities.files.processing.processor import FileProcessor
+
+
+# Minimal valid PNG: 8x8 pixel RGB image (valid for PIL)
+MINIMAL_PNG = bytes([
+    0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d,
+    0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x08,
+    0x08, 0x02, 0x00, 0x00, 0x00, 0x4b, 0x6d, 0x29, 0xdc, 0x00, 0x00, 0x00,
+    0x12, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x63, 0xfc, 0xcf, 0x80, 0x1d,
+    0x30, 0xe1, 0x10, 0x1f, 0xa4, 0x12, 0x00, 0xcd, 0x41, 0x01, 0x0f, 0xe8,
+    0x41, 0xe2, 0x6f, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae,
+    0x42, 0x60, 0x82,
+])
+
+# Minimal valid PDF
+MINIMAL_PDF = (
+    b"%PDF-1.4\n1 0 obj<</Type/Catalog/Pages 2 0 R>>endobj "
+    b"2 0 obj<</Type/Pages/Kids[3 0 R]/Count 1>>endobj "
+    b"3 0 obj<</Type/Page/MediaBox[0 0 612 792]/Parent 2 0 R>>endobj "
+    b"xref\n0 4\n0000000000 65535 f \n0000000009 00000 n \n"
+    b"0000000052 00000 n \n0000000101 00000 n \n"
+    b"trailer<</Size 4/Root 1 0 R>>\nstartxref\n178\n%%EOF"
+)
+
+
+class TestFileProcessorInit:
+    """Tests for FileProcessor initialization."""
+
+    def test_init_with_constraints(self):
+        """Test initialization with ProviderConstraints."""
+        processor = FileProcessor(constraints=ANTHROPIC_CONSTRAINTS)
+
+        assert processor.constraints == ANTHROPIC_CONSTRAINTS
+
+    def test_init_with_provider_string(self):
+        """Test initialization with provider name string."""
+        processor = FileProcessor(constraints="anthropic")
+
+        assert processor.constraints == ANTHROPIC_CONSTRAINTS
+
+    def test_init_with_unknown_provider(self):
+        """Test initialization with unknown provider sets constraints to None."""
+        processor = FileProcessor(constraints="unknown")
+
+        assert processor.constraints is None
+
+    def test_init_with_none_constraints(self):
+        """Test initialization with None constraints."""
+        processor = FileProcessor(constraints=None)
+
+        assert processor.constraints is None
+
+
+class TestFileProcessorValidate:
+    """Tests for FileProcessor.validate method."""
+
+    def test_validate_valid_file(self):
+        """Test validating a valid file returns no errors."""
+        processor = FileProcessor(constraints=ANTHROPIC_CONSTRAINTS)
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"))
+
+        errors = processor.validate(file)
+
+        assert len(errors) == 0
+
+    def test_validate_without_constraints(self):
+        """Test validating without constraints returns empty list."""
+        processor = FileProcessor(constraints=None)
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"))
+
+        errors = processor.validate(file)
+
+        assert len(errors) == 0
+
+    def test_validate_strict_raises_on_error(self):
+        """Test STRICT mode raises on validation error."""
+        constraints = ProviderConstraints(
+            name="test",
+            image=ImageConstraints(max_size_bytes=10),
+        )
+        processor = FileProcessor(constraints=constraints)
+        # Set mode to strict on the file
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="strict")
+
+        with pytest.raises(FileTooLargeError):
+            processor.validate(file)
+
+
+class TestFileProcessorProcess:
+    """Tests for FileProcessor.process method."""
+
+    def test_process_valid_file(self):
+        """Test processing a valid file returns it unchanged."""
+        processor = FileProcessor(constraints=ANTHROPIC_CONSTRAINTS)
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"))
+
+        result = processor.process(file)
+
+        assert result == file
+
+    def test_process_without_constraints(self):
+        """Test processing without constraints returns file unchanged."""
+        processor = FileProcessor(constraints=None)
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"))
+
+        result = processor.process(file)
+
+        assert result == file
+
+    def test_process_strict_raises_on_error(self):
+        """Test STRICT mode raises on processing error."""
+        constraints = ProviderConstraints(
+            name="test",
+            image=ImageConstraints(max_size_bytes=10),
+        )
+        processor = FileProcessor(constraints=constraints)
+        # Set mode to strict on the file
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="strict")
+
+        with pytest.raises(FileTooLargeError):
+            processor.process(file)
+
+    def test_process_warn_returns_file(self):
+        """Test WARN mode returns file with warning."""
+        constraints = ProviderConstraints(
+            name="test",
+            image=ImageConstraints(max_size_bytes=10),
+        )
+        processor = FileProcessor(constraints=constraints)
+        # Set mode to warn on the file
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="warn")
+
+        result = processor.process(file)
+
+        assert result == file
+
+
+class TestFileProcessorProcessFiles:
+    """Tests for FileProcessor.process_files method."""
+
+    def test_process_files_multiple(self):
+        """Test processing multiple files."""
+        processor = FileProcessor(constraints=ANTHROPIC_CONSTRAINTS)
+        files = {
+            "image1": ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test1.png")),
+            "image2": ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test2.png")),
+        }
+
+        result = processor.process_files(files)
+
+        assert len(result) == 2
+        assert "image1" in result
+        assert "image2" in result
+
+    def test_process_files_empty(self):
+        """Test processing empty files dict."""
+        processor = FileProcessor(constraints=ANTHROPIC_CONSTRAINTS)
+
+        result = processor.process_files({})
+
+        assert result == {}
+
+
+class TestFileHandlingEnum:
+    """Tests for FileHandling enum."""
+
+    def test_enum_values(self):
+        """Test all enum values are accessible."""
+        assert FileHandling.STRICT.value == "strict"
+        assert FileHandling.AUTO.value == "auto"
+        assert FileHandling.WARN.value == "warn"
+        assert FileHandling.CHUNK.value == "chunk"
+
+
+class TestFileProcessorPerFileMode:
+    """Tests for per-file mode handling."""
+
+    def test_file_default_mode_is_auto(self):
+        """Test that files default to auto mode."""
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"))
+        assert file.mode == "auto"
+
+    def test_file_custom_mode(self):
+        """Test setting custom mode on file."""
+        file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="strict")
+        assert file.mode == "strict"
+
+    def test_processor_respects_file_mode(self):
+        """Test processor uses each file's mode setting."""
+        constraints = ProviderConstraints(
+            name="test",
+            image=ImageConstraints(max_size_bytes=10),
+        )
+        processor = FileProcessor(constraints=constraints)
+
+        # File with strict mode should raise
+        strict_file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="strict")
+        with pytest.raises(FileTooLargeError):
+            processor.process(strict_file)
+
+        # File with warn mode should not raise
+        warn_file = ImageFile(source=FileBytes(data=MINIMAL_PNG, filename="test.png"), mode="warn")
+        result = processor.process(warn_file)
+        assert result == warn_file