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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package difftest supplies a set of tests that will operate on any
// implementation of a diff algorithm as exposed by
// "golang.org/x/tools/internal/lsp/diff"
package difftest
import (
"fmt"
"testing"
"golang.org/x/tools/internal/lsp/diff"
"golang.org/x/tools/internal/span"
)
const (
FileA = "from"
FileB = "to"
UnifiedPrefix = "--- " + FileA + "\n+++ " + FileB + "\n"
)
var TestCases = []struct {
Name, In, Out, Unified string
Edits, LineEdits []diff.TextEdit
NoDiff bool
}{{
Name: "empty",
In: "",
Out: "",
}, {
Name: "no_diff",
In: "gargantuan\n",
Out: "gargantuan\n",
}, {
Name: "replace_all",
In: "fruit\n",
Out: "cheese\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-fruit
+cheese
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(0, 5), NewText: "cheese"}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 6), NewText: "cheese\n"}},
}, {
Name: "insert_rune",
In: "gord\n",
Out: "gourd\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-gord
+gourd
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(2, 2), NewText: "u"}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 5), NewText: "gourd\n"}},
}, {
Name: "delete_rune",
In: "groat\n",
Out: "goat\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-groat
+goat
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(1, 2), NewText: ""}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 6), NewText: "goat\n"}},
}, {
Name: "replace_rune",
In: "loud\n",
Out: "lord\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-loud
+lord
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(2, 3), NewText: "r"}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 5), NewText: "lord\n"}},
}, {
Name: "replace_partials",
In: "blanket\n",
Out: "bunker\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-blanket
+bunker
`[1:],
Edits: []diff.TextEdit{
{Span: newSpan(1, 3), NewText: "u"},
{Span: newSpan(6, 7), NewText: "r"},
},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 8), NewText: "bunker\n"}},
}, {
Name: "insert_line",
In: "1: one\n3: three\n",
Out: "1: one\n2: two\n3: three\n",
Unified: UnifiedPrefix + `
@@ -1,2 +1,3 @@
1: one
+2: two
3: three
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(7, 7), NewText: "2: two\n"}},
}, {
Name: "replace_no_newline",
In: "A",
Out: "B",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-A
\ No newline at end of file
+B
\ No newline at end of file
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(0, 1), NewText: "B"}},
}, {
Name: "add_end",
In: "A",
Out: "AB",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-A
\ No newline at end of file
+AB
\ No newline at end of file
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(1, 1), NewText: "B"}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 1), NewText: "AB"}},
}, {
Name: "add_newline",
In: "A",
Out: "A\n",
Unified: UnifiedPrefix + `
@@ -1 +1 @@
-A
\ No newline at end of file
+A
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(1, 1), NewText: "\n"}},
LineEdits: []diff.TextEdit{{Span: newSpan(0, 1), NewText: "A\n"}},
}, {
Name: "delete_front",
In: "A\nB\nC\nA\nB\nB\nA\n",
Out: "C\nB\nA\nB\nA\nC\n",
Unified: UnifiedPrefix + `
@@ -1,7 +1,6 @@
-A
-B
C
+B
A
B
-B
A
+C
`[1:],
Edits: []diff.TextEdit{
{Span: newSpan(0, 4), NewText: ""},
{Span: newSpan(6, 6), NewText: "B\n"},
{Span: newSpan(10, 12), NewText: ""},
{Span: newSpan(14, 14), NewText: "C\n"},
},
NoDiff: true, // diff algorithm produces different delete/insert pattern
},
{
Name: "replace_last_line",
In: "A\nB\n",
Out: "A\nC\n\n",
Unified: UnifiedPrefix + `
@@ -1,2 +1,3 @@
A
-B
+C
+
`[1:],
Edits: []diff.TextEdit{{Span: newSpan(2, 3), NewText: "C\n"}},
LineEdits: []diff.TextEdit{{Span: newSpan(2, 4), NewText: "C\n\n"}},
},
{
Name: "multiple_replace",
In: "A\nB\nC\nD\nE\nF\nG\n",
Out: "A\nH\nI\nJ\nE\nF\nK\n",
Unified: UnifiedPrefix + `
@@ -1,7 +1,7 @@
A
-B
-C
-D
+H
+I
+J
E
F
-G
+K
`[1:],
Edits: []diff.TextEdit{
{Span: newSpan(2, 8), NewText: "H\nI\nJ\n"},
{Span: newSpan(12, 14), NewText: "K\n"},
},
NoDiff: true, // diff algorithm produces different delete/insert pattern
},
}
func init() {
// expand all the spans to full versions
// we need them all to have their line number and column
for _, tc := range TestCases {
c := span.NewContentConverter("", []byte(tc.In))
for i := range tc.Edits {
tc.Edits[i].Span, _ = tc.Edits[i].Span.WithAll(c)
}
for i := range tc.LineEdits {
tc.LineEdits[i].Span, _ = tc.LineEdits[i].Span.WithAll(c)
}
}
}
func DiffTest(t *testing.T, compute diff.ComputeEdits) {
t.Helper()
for _, test := range TestCases {
t.Run(test.Name, func(t *testing.T) {
t.Helper()
edits := compute(span.URIFromPath("/"+test.Name), test.In, test.Out)
got := diff.ApplyEdits(test.In, edits)
unified := fmt.Sprint(diff.ToUnified(FileA, FileB, test.In, edits))
if got != test.Out {
t.Errorf("got patched:\n%v\nfrom diff:\n%v\nexpected:\n%v", got, unified, test.Out)
}
if !test.NoDiff && unified != test.Unified {
t.Errorf("got diff:\n%v\nexpected:\n%v", unified, test.Unified)
}
})
}
}
func newSpan(start, end int) span.Span {
return span.New("", span.NewPoint(0, 0, start), span.NewPoint(0, 0, end))
}