You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: parser_test.go
    path of file: ./repos/trivy/pkg/licensing/expression
    
    the code of the file until where you have to start completion: package expression

import (
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestParse(t *testing.T) {
	tests := []struct {
		name    string
		input   string
		want    Expression
		wantStr string
		wantErr string
	}{
		{
			name:  "single license",
			input: "Public Domain",
			want: SimpleExpr{
				license: "Public Domain",
			},
			wantStr: "Public Domain",
		},
		{
			name:  "tag:value license",
			input: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
			want: SimpleExpr{
				license: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
			},
			wantStr: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
		},
		{
			name:  "symbols",
			input: "Public ._-+",
			want: SimpleExpr{
				license: "Public ._-",
				hasPlus: true,
			},
			wantStr: "Public ._-+",
		},
		{
			name:  "multi licenses",
			input: "Public Domain AND ( GPLv2+ or AFL ) AND LGPLv2+ with distribution exceptions",
			want: CompoundExpr{
				left: CompoundExpr
    
func TestParse(t *testing.T) {
	tests := []struct {
		name    string
		input   string
		want    Expression
		wantStr string
		wantErr string
	}{
		{
			name:  "single license",
			input: "Public Domain",
			want: SimpleExpr{
				license: "Public Domain",
			},
			wantStr: "Public Domain",
		},
		{
			name:  "tag:value license",
			input: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
			want: SimpleExpr{
				license: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
			},
			wantStr: "DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2",
		},
		{
			name:  "symbols",
			input: "Public ._-+",
			want: SimpleExpr{
				license: "Public ._-",
				hasPlus: true,
			},
			wantStr: "Public ._-+",
		},
		{
			name:  "multi licenses",
			input: "Public Domain AND ( GPLv2+ or AFL ) AND LGPLv2+ with distribution exceptions",
			want: CompoundExpr{
				left: CompoundExpr{
					left: SimpleExpr{
						license: "Public Domain",
					},
					conjunction: Token{
						token:   AND,
						literal: "AND",
					},
					right: CompoundExpr{
						left: SimpleExpr{
							license: "GPLv2",
							hasPlus: true,
						},
						conjunction: Token{
							token:   OR,
							literal: "or",
						},
						right: SimpleExpr{
							license: "AFL",
						},
					},
				},
				conjunction: Token{
					token:   AND,
					literal: "AND",
				},
				right: CompoundExpr{
					left: SimpleExpr{
						license: "LGPLv2",
						hasPlus: true,
					},
					conjunction: Token{
						token:   WITH,
						literal: "with",
					},
					right: SimpleExpr{
						license: "distribution exceptions",
					},
				},
			},
			wantStr: "Public Domain AND (GPLv2+ or AFL) AND LGPLv2+ with distribution exceptions",
		},
		{
			name:  "nested licenses",
			input: "Public Domain AND ( GPLv2+ or AFL AND ( CC0 or LGPL1.0) )",
			want: CompoundExpr{
				left: SimpleExpr{
					license: "Public Domain",
				},
				conjunction: Token{
					token:   AND,
					literal: "AND",
				},
				right: CompoundExpr{
					left: SimpleExpr{
						license: "GPLv2",
						hasPlus: true,
					},
					conjunction: Token{
						token:   OR,
						literal: "or",
					},
					right: CompoundExpr{
						left: SimpleExpr{
							license: "AFL",
						},
						conjunction: Token{
							token:   AND,
							literal: "AND",
						},
						right: CompoundExpr{
							left: SimpleExpr{
								license: "CC0",
							},
							conjunction: Token{
								token:   OR,
								literal: "or",
							},
							right: SimpleExpr{
								license: "LGPL1.0",
							},
						},
					},
				},
			},
			wantStr: "Public Domain AND (GPLv2+ or AFL AND (CC0 or LGPL1.0))",
		},
		{
			name:    "bad path close bracket not found",
			input:   "Public Domain AND ( GPLv2+ ",
			wantErr: "syntax error",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			l := NewLexer(strings.NewReader(tt.input))
			ret := yyParse(l)
			err := l.Err()
			if tt.wantErr != "" {
				assert.Equal(t, ret, 1)
				assert.ErrorContains(t, err, tt.wantErr)
				return
			}
			require.NoError(t, err)
			assert.Equal(t, tt.want, l.result)
			assert.Equal(t, tt.wantStr, l.result.String())
		})
	}
}