go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/testing/assert/structuraldiff/structural_diff_test.go (about)

     1  // Copyright 2024 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package structuraldiff
    16  
    17  import (
    18  	"strings"
    19  	"testing"
    20  
    21  	"github.com/google/go-cmp/cmp"
    22  	"github.com/sergi/go-diff/diffmatchpatch"
    23  
    24  	"go.chromium.org/luci/common/testing/typed"
    25  )
    26  
    27  // TestDebugCompare compares two values and checks to see if the result is what we expect.
    28  //
    29  // This test is sensitive to small changes in how the Result is represented.
    30  func TestDebugCompare(t *testing.T) {
    31  	t.Parallel()
    32  
    33  	cases := []struct {
    34  		name   string
    35  		left   any
    36  		right  any
    37  		result *Result
    38  	}{
    39  		{
    40  			name:   "equal",
    41  			left:   10,
    42  			right:  10,
    43  			result: nil,
    44  		},
    45  		{
    46  			name:  "different",
    47  			left:  10,
    48  			right: 27,
    49  			result: &Result{
    50  				diffs: []diffmatchpatch.Diff{
    51  					{Type: diffmatchpatch.DiffDelete, Text: "10"},
    52  					{Type: diffmatchpatch.DiffInsert, Text: "27"},
    53  				},
    54  			},
    55  		},
    56  		{
    57  			name:  "different types but similar string representation.",
    58  			left:  10,
    59  			right: "10",
    60  			result: &Result{
    61  				diffs: []diffmatchpatch.Diff{
    62  					{Type: diffmatchpatch.DiffInsert, Text: `"`},
    63  					{Text: "10"},
    64  					{Type: diffmatchpatch.DiffInsert, Text: `"`},
    65  				},
    66  			},
    67  		},
    68  	}
    69  
    70  	for _, tt := range cases {
    71  		tt := tt
    72  		t.Run(tt.name, func(t *testing.T) {
    73  			t.Parallel()
    74  
    75  			got := DebugCompare[any](tt.left, tt.right)
    76  			want := tt.result
    77  
    78  			if diff := typed.Got(got).Want(want).Options(cmp.AllowUnexported(Result{})).Diff(); diff != "" {
    79  				t.Errorf("unexpected diff (-want +got): %s", diff)
    80  			}
    81  		})
    82  	}
    83  }
    84  
    85  // TestToString tests rendering a result as a string
    86  func TestToString(t *testing.T) {
    87  	t.Parallel()
    88  
    89  	cases := []struct {
    90  		name   string
    91  		result *Result
    92  		output string
    93  	}{
    94  		{
    95  			name:   "empty",
    96  			result: nil,
    97  			output: "",
    98  		},
    99  		{
   100  			name:   "simple",
   101  			result: DebugCompare[string]("a", "b"),
   102  			output: strings.Join([]string{
   103  				"Delete a\n",
   104  				"Insert b\n",
   105  			}, ""),
   106  		},
   107  	}
   108  
   109  	for _, tt := range cases {
   110  		tt := tt
   111  		t.Run(tt.name, func(t *testing.T) {
   112  			t.Parallel()
   113  
   114  			if diff := typed.Got(tt.result.String()).Want(tt.output).Diff(); diff != "" {
   115  				t.Errorf("unexpected diff (-want +got): %s", diff)
   116  			}
   117  		})
   118  	}
   119  }