write_test.go

package dicom

import (
	"bytes"
	"encoding/binary"
	"io/ioutil"
	"os"
	"testing"

	"github.com/google/go-cmp/cmp/cmpopts"

	"github.com/google/go-cmp/cmp"

	"github.com/suyashkumar/dicom/pkg/dicomio"
	"github.com/suyashkumar/dicom/pkg/tag"
	"github.com/suyashkumar/dicom/pkg/uid"
)

// TestWrite tests the write package by ensuring that it is consistent with the
// Parse implementation. In particular, it is tested by writing out known
// collections of Element and reading them back in using the Parse API and
// ensuing the read in collection is equal to the initial collection.
//
// This also serves to test that the Parse implementation is consistent with the
// Write implementation (e.g. it kinda goes both ways and covers Parse too).
func TestWrite(t *testing.T) {
	cases := []struct {
		name          string
		dataset       Dataset
		extraElems    []*Element
		expectedError error
		opts          []WriteOption
		cmpOpts       []cmp.Option
	}{
		{
			name: "basic types",
			dataset: Dataset{Elements: []*Element{
				mustNewElement(tag.MediaStorageSOPClassUID, []string{"1.2.840.10008.5.1.4.1.1.1.2"}),
				mustNewElement(tag.MediaStorageSOPInstanceUID, []string{"1.2.3.4.5.6.7"}),
				mustNewElement(tag.TransferSyntaxUID, []string{uid.ImplicitVRLittleEndian}),
				mustNewElement(tag.PatientName, []string{"Bob", "Jones"}),
				mustNewElement(tag.Rows, []int{128}),
				mustNewElement(tag.FloatingPointValue, []float64{128.10}),
				mustNewElement(tag.DimensionIndexPointer, []int{32, 36950}),
			}},
			expectedError: nil,
		},
		{
			name: "sequence (2 Items with 2 values each)",
			dataset: Dataset{Elements: []*Element{
				mustNewElement(tag.MediaStorageSOPClassUID, []string{"1.2.840.10008.5.1.4.1.1.1.2"}),
				mustNewElement(tag.MediaStorageSOPInstanceUID, []string{"1.2.3.4.5.6.7"}),
				mustNewElement(tag.TransferSyntaxUID, []string{uid.ImplicitVRLittleEndian}),
				mustNewElement(tag.PatientName, []string{"Bob", "Jones"}),
				makeSequenceElement(tag.AddOtherSequence, [][]*Element{
					// Item 1.
					{
						{
							Tag:                    tag.PatientName,
							ValueRepresentation:    tag.VRStringList,
							RawValueRepresentation: "PN",
							Value: &stringsValue{
								value: []string{"Bob", "Jones"},
							},
						},
						{
							Tag:                    tag.Rows,
							ValueRepresentation:    tag.VRUInt16List,
							RawValueRepresentation: "US",
							Value: &intsValue{
								value: []int{100},
							},
						},
					},
					// Item 2.
					{
						{
							Tag:                    tag.PatientName,
							ValueRepresentation:    tag.VRStringList,
							RawValueRepresentation: "PN",
							Value: &stringsValue{
								value: []string{"Bob", "Jones"},
							},
						},
						{
							Tag:                    tag.Rows,
							ValueRepresentation:    tag.VRUInt16List,
							RawValueRepresentation: "US",
							Value: &intsValue{
								value: []int{100},
							},
						},
					},
				}),
			}},
			expectedError: nil,
		},
		{
			name: "nested sequences",
			dataset: Dataset{Elements: []*Element{
				mustNewElement(tag.MediaStorageSOPClassUID, []string{"1.2.840.10008.5.1.4.1.1.1.2"}),
				mustNewElement(tag.MediaStorageSOPInstanceUID, []string{"1.2.3.4.5.6.7"}),
				mustNewElement(tag.TransferSyntaxUID, []string{uid.ImplicitVRLittleEndian}),
				mustNewElement(tag.PatientName, []string{"Bob", "Jones"}),
				makeSequenceElement(tag.AddOtherSequence, [][]*Element{
					// Item 1.
					{
						{
							Tag:                    tag.PatientName,
							ValueRepresentation:    tag.VRStringList,
							RawValueRepresentation: "PN",
							Value: &stringsValue{
								value: []string{"Bob", "Jones"},
							},
						},
						// Nested Sequence.
						makeSequenceElement(tag.AnatomicRegionSequence, [][]*Element{
							{
								{
									Tag:                    tag.PatientName,
									ValueRepresentation:    tag.VRStringList,
									RawValueRepresentation: "PN",
									Value: &stringsValue{
										value: []string{"Bob", "Jones"},
									},
								},
							},
						}),
					},
				}),
			}},
			expectedError: nil,
		},
		{
			name: "without transfer syntax",
			dataset: Dataset{Elements: []*Element{
				mustNewElement(tag.MediaStorageSOPClassUID, []string{"1.2.840.10008.5.1.4.1.1.1.2"}),
				mustNewElement(tag.MediaStorageSOPInstanceUID, []string{"1.2.3.4.5.6.7"}),
				mustNewElement(tag.PatientName, []string{"Bob", "Jones"}),
				mustNewElement(tag.Rows, []int{128}),
				mustNewElement(tag.FloatingPointValue, []float64{128.10}),
			}},
			expectedError: ErrorElementNotFound,
		},
		{
			name: "without transfer syntax with DefaultMissingTransferSyntax",
			dataset: Dataset{Elements: []*Element{
				mustNewElement(tag.MediaStorageSOPClassUID, []string{"1.2.840.10008.5.1.4.1.1.1.2"}),
				mustNewElement(tag.MediaStorageSOPInstanceUID, []string{"1.2.3.4.5.6.7"}),
				mustNewElement(tag.PatientName, []string{"Bob", "Jones"}),
				mustNewElement(tag.Rows, []int{128}),
				mustNewElement(tag.FloatingPointValue, []float64{128.10}),
			}},
			// This gets inserted if DefaultMissingTransferSyntax is provided:
			extraElems:    []*Element{mustNewElement(tag.TransferSyntaxUID, []string{uid.ImplicitVRLittleEndian})},
			expectedError: nil,
			opts:          []WriteOption{DefaultMissingTransferSyntax()},
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			file, err := ioutil.TempFile("", "write_test.dcm")
			if err != nil {
				t.Fatalf("Unexpected error when creating tempfile: %v", err)
			}
			if err = Write(file, tc.dataset, tc.opts...); err != tc.expectedError {
				t.Errorf("Write(%v): unexpected error. got: %v, want: %v", tc.dataset, err, tc.expectedError)
			}
			file.Close()

			// Read the data back in and check for equality to the tc.dataset:
			if tc.expectedError == nil {
				f, err := os.Open(file.Name())
				if err != nil {
					t.Fatalf("Unexpected error opening file %s: %v", file.Name(), err)
				}
				info, err := f.Stat()
				if err != nil {
					t.Fatalf("Unexpected error state file: %s: %v", file.Name(), err)
				}

				readDS, err := Parse(f, info.Size(), nil)
				if err != nil {
					t.Errorf("Parse of written file, unexpected error: %v", err)
				}

				wantElems := append(tc.dataset.Elements, tc.extraElems...)

				cmpOpts := []cmp.Option{
					cmp.AllowUnexported(allValues...),
					cmpopts.IgnoreFields(Element{}, "ValueLength"),
					cmpopts.IgnoreSliceElements(func(e *Element) bool { return e.Tag == tag.FileMetaInformationGroupLength }),
					cmpopts.SortSlices(func(x, y *Element) bool { return x.Tag.Compare(y.Tag) == 1 }),
				}
				cmpOpts = append(cmpOpts, tc.cmpOpts...)

				if diff := cmp.Diff(
					readDS.Elements,
					wantElems,
					cmpOpts...,
				); diff != "" {
					t.Errorf("Reading back written dataset led to unexpected diff from source data: %s", diff)
				}
			}
		})
	}
}

func TestVerifyVR(t *testing.T) {
	cases := []struct {
		name    string
		tg      tag.Tag
		inVR    string
		wantVR  string
		wantErr bool
	}{
		{
			name:    "wrong vr",
			tg:      tag.FileMetaInformationGroupLength,
			inVR:    "OB",
			wantVR:  "",
			wantErr: true,
		},
		{
			name:    "no vr",
			tg:      tag.FileMetaInformationGroupLength,
			inVR:    "",
			wantVR:  "UL",
			wantErr: false,
		},
		{
			name: "made up tag",
			tg: tag.Tag{
				Group:   0x9999,
				Element: 0x9999,
			},
			inVR:    "",
			wantVR:  "UN",
			wantErr: false,
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			vr, err := verifyVROrDefault(tc.tg, tc.inVR)
			if (err != nil && !tc.wantErr) || (err == nil && tc.wantErr) {
				t.Errorf("verifyVROrDefault(%v, %v), got err: %v but want err: %v", tc.tg, tc.inVR, err, tc.wantErr)
			}
			if vr != tc.wantVR {
				t.Errorf("verifyVROrDefault(%v, %v): unexpected vr. got: %v, want: %v", tc.tg, tc.inVR, vr, tc.wantVR)
			}
		})
	}
}

func TestVerifyValueType(t *testing.T) {
	cases := []struct {
		name      string
		tg        tag.Tag
		value     Value
		vr        string
		wantError bool
	}{
		{
			name:      "valid",
			tg:        tag.FileMetaInformationGroupLength,
			value:     mustNewValue([]int{128}),
			vr:        "UL",
			wantError: false,
		},
		{
			name:      "invalid vr",
			tg:        tag.FileMetaInformationGroupLength,
			value:     mustNewValue([]int{128}),
			vr:        "NA",
			wantError: true,
		},
		{
			name:      "wrong valueType",
			tg:        tag.FileMetaInformationGroupLength,
			value:     mustNewValue([]string{"str"}),
			vr:        "UL",
			wantError: true,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			err := verifyValueType(tc.tg, tc.value, tc.vr)
			if (err != nil && !tc.wantError) || (err == nil && tc.wantError) {
				t.Errorf("verifyValueType(%v, %v, %v), got err: %v but want err: %v", tc.tg, tc.value, tc.vr, err, tc.wantError)
			}
		})
	}
}

func TestWriteFloats(t *testing.T) {
	// TODO: add additional cases
	cases := []struct {
		name         string
		value        Value
		vr           string
		expectedData []byte
		expectedErr  error
	}{
		{
			name:  "float64s",
			value: &floatsValue{value: []float64{20.1019, 21.212}},
			vr:    "FD",
			// TODO: improve test expectation
			expectedData: []byte{0x60, 0x76, 0x4f, 0x1e, 0x16, 0x1a, 0x34, 0x40, 0x83, 0xc0, 0xca, 0xa1, 0x45, 0x36, 0x35, 0x40},
			expectedErr:  nil,
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			buf := bytes.Buffer{}
			w := dicomio.NewWriter(&buf, binary.LittleEndian, false)
			err := writeFloats(w, tc.value, tc.vr)
			if err != tc.expectedErr {
				t.Errorf("writeFloats(%v, %s) returned unexpected err. got: %v, want: %v", tc.value, tc.vr, err, tc.expectedErr)
			}
			if diff := cmp.Diff(tc.expectedData, buf.Bytes()); diff != "" {
				t.Errorf("writeFloats(%v, %s) wrote unexpected data. diff: %s", tc.value, tc.vr, diff)
				t.Errorf("% x", buf.Bytes())
			}
		})
	}

}