cmd/autocorrelator/compare/compare_test.go

// Copyright 2021 The Fuchsia Authors.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package compare

import (
	"testing"

	"github.com/texttheater/golang-levenshtein/levenshtein"
)

func TestLevenshteinComparator(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name          string
		s1            string
		s2            string
		expectedScore float64
	}{
		{
			name: "substitution",
			s1:   "[9/10] ACTION\n\n//path/to/binary(//build/foobar:x64)",
			s2:   "[8/11] ACTION\n\n//path/to/binary(//build/foobar:x64)",
			// ratio = (len(s1) + len(s2) - levDist) / len(s1) + len(s2).
			// Each substition costs 2.
			expectedScore: float64(51+51-4) / (51 + 51),
		},
		{
			name: "addition and subtraction",
			s1:   "[9/10] ACTION\n\n//path/to/binary(//build/foobar:x64)",
			s2:   "[8/11] ACTION\n\n//path/to/binary(//build/foo:x64)\n\nFAILED: binary exe.unstripped/binary",
			// Each addition or subtraction costs 1.
			expectedScore: float64(51+86-45) / (51 + 86),
		},
		// The order of inputs should not influence the score.
		{
			name:          "reordering",
			s1:            "[8/11] ACTION\n\n//path/to/binary(//build/foo:x64)\n\nFAILED: binary exe.unstripped/binary",
			s2:            "[9/10] ACTION\n\n//path/to/binary(//build/foobar:x64)",
			expectedScore: float64(51+86-45) / (51 + 86),
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			lc := LevenshteinComparator{Opts: levenshtein.DefaultOptions}
			score := lc.Compare(test.s1, test.s2)
			if score != test.expectedScore {
				t.Fatalf("expected score %0.3f, got %0.3f", test.expectedScore, score)
			}
		})
	}
}