Began implementing the befunge field data structure

1 files changed, 154 insertions, 0 deletions

diff --git a/pkg/field/field_test.go b/pkg/field/field_test.go
new file mode 100644
index 0000000..52f7d80
--- /dev/null
+++ b/pkg/field/field_test.go
@@ -0,0 +1,154 @@
+package field
+
+import (
+	"io"
+	"os"
+	"testing"
+	"testing/iotest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadFile(t *testing.T) {
+	// minimal b98 file
+	minimalField := Field{
+		firstLineIndex: 0,
+		length:         1,
+		lines: []Line{
+			Line{
+				firstColumnIndex: 0,
+				length:           1,
+				columns:          []byte{'@'},
+			},
+		},
+	}
+	// hello b98 file
+	helloField := Field{
+		firstLineIndex: 0,
+		length:         1,
+		lines: []Line{
+			Line{
+				firstColumnIndex: 0,
+				length:           24,
+				columns:          []byte{'6', '4', '+', '"', '!', 'd', 'l', 'r', 'o', 'W', ' ', ',', 'o', 'l', 'l', 'e', 'H', '"', '>', ':', '#', ',', '_', '@'},
+			},
+		},
+	}
+	// factorial b98 file
+	factorialField := Field{
+		firstLineIndex: 0,
+		length:         2,
+		lines: []Line{
+			Line{
+				firstColumnIndex: 0,
+				length:           15,
+				columns:          []byte{'&', '>', ':', '1', '-', ':', 'v', ' ', 'v', ' ', '*', '_', '$', '.', '@'},
+			},
+			Line{
+				firstColumnIndex: 1,
+				length:           11,
+				columns:          []byte{'^', ' ', ' ', ' ', ' ', '_', '$', '>', '\\', ':', '^'},
+			},
+		},
+	}
+	// dna b98 file
+	dnaField := Field{
+		firstLineIndex: 0,
+		length:         8,
+		lines: []Line{
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'7', '^', 'D', 'N', '>', 'v', 'A'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'v', '_', '#', 'v', '?', ' ', 'v'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'7', '^', '<', '"', '"', '"', '"'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'3', ' ', ' ', 'A', 'C', 'G', 'T'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'9', '0', '!', '"', '"', '"', '"'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'4', '*', ':', '>', '>', '>', 'v'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'+', '8', '^', '-', '1', ',', '<'},
+			},
+			Line{
+				firstColumnIndex: 0,
+				length:           7,
+				columns:          []byte{'>', ' ', ',', '+', ',', '@', ')'},
+			},
+		},
+	}
+	// \r\n file b98 file
+	rnField := Field{
+		firstLineIndex: 0,
+		length:         1,
+		lines: []Line{
+			Line{
+				firstColumnIndex: 0,
+				length:           24,
+				columns:          []byte{'6', '4', '+', '"', '!', 'd', 'l', 'r', 'o', 'W', ' ', ',', 'o', 'l', 'l', 'e', 'H', '"', '>', ':', '#', ',', '_', '@'},
+			},
+		},
+	}
+	// Test cases
+	type addError func(r io.Reader) io.Reader
+	testCases := []struct {
+		name          string
+		input         string
+		inputAddError addError
+		expected      *Field
+		expectedError error
+	}{
+		{"Empty file", "test_data/empty.b98", nil, nil, &DecodeError{}},
+		{"Invalid file content", "test_data/invalid.b98", nil, nil, &DecodeError{}},
+		{"io error", "test_data/minimal.b98", iotest.TimeoutReader, nil, &ReadError{}},
+		{"minimal", "test_data/minimal.b98", nil, &minimalField, nil},
+		{"hello", "test_data/hello.b98", nil, &helloField, nil},
+		{"factorial", "test_data/factorial.b98", nil, &factorialField, nil},
+		{"dna", "test_data/dna.b98", nil, &dnaField, nil},
+		{"\\r\\n file", "test_data/rn.b98", nil, &rnField, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			var fd io.Reader
+			file, err := os.Open(tc.input)
+			require.NoError(t, err, "Failed to open file")
+			defer file.Close()
+			if tc.inputAddError != nil {
+				fd = tc.inputAddError(file)
+			} else {
+				fd = file
+			}
+			valid, err := LoadFile(fd)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				requireErrorTypeMatch(t, err, tc.expectedError)
+				require.Nil(t, valid)
+			} else {
+				require.NoError(t, err)
+			}
+			assert.Equal(t, tc.expected, valid, "Invalid value")
+		})
+	}
+}