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Diffstat (limited to 'internal/diff/difftest/difftest.go')
| -rw-r--r-- | internal/diff/difftest/difftest.go | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/internal/diff/difftest/difftest.go b/internal/diff/difftest/difftest.go new file mode 100644 index 000000000..4a251111b --- /dev/null +++ b/internal/diff/difftest/difftest.go @@ -0,0 +1,289 @@ +// 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/diff" +package difftest + +// There are two kinds of tests, semantic tests, and 'golden data' tests. +// The semantic tests check that the computed diffs transform the input to +// the output, and that 'patch' accepts the computed unified diffs. +// The other tests just check that Edits and LineEdits haven't changed +// unexpectedly. These fields may need to be changed when the diff algorithm +// changes. + +import ( + "testing" + + "golang.org/x/tools/internal/diff" +) + +const ( + FileA = "from" + FileB = "to" + UnifiedPrefix = "--- " + FileA + "\n+++ " + FileB + "\n" +) + +var TestCases = []struct { + Name, In, Out, Unified string + Edits, LineEdits []diff.Edit + 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.Edit{{Start: 0, End: 5, New: "cheese"}}, + LineEdits: []diff.Edit{{Start: 0, End: 6, New: "cheese\n"}}, +}, { + Name: "insert_rune", + In: "gord\n", + Out: "gourd\n", + Unified: UnifiedPrefix + ` +@@ -1 +1 @@ +-gord ++gourd +`[1:], + Edits: []diff.Edit{{Start: 2, End: 2, New: "u"}}, + LineEdits: []diff.Edit{{Start: 0, End: 5, New: "gourd\n"}}, +}, { + Name: "delete_rune", + In: "groat\n", + Out: "goat\n", + Unified: UnifiedPrefix + ` +@@ -1 +1 @@ +-groat ++goat +`[1:], + Edits: []diff.Edit{{Start: 1, End: 2, New: ""}}, + LineEdits: []diff.Edit{{Start: 0, End: 6, New: "goat\n"}}, +}, { + Name: "replace_rune", + In: "loud\n", + Out: "lord\n", + Unified: UnifiedPrefix + ` +@@ -1 +1 @@ +-loud ++lord +`[1:], + Edits: []diff.Edit{{Start: 2, End: 3, New: "r"}}, + LineEdits: []diff.Edit{{Start: 0, End: 5, New: "lord\n"}}, +}, { + Name: "replace_partials", + In: "blanket\n", + Out: "bunker\n", + Unified: UnifiedPrefix + ` +@@ -1 +1 @@ +-blanket ++bunker +`[1:], + Edits: []diff.Edit{ + {Start: 1, End: 3, New: "u"}, + {Start: 6, End: 7, New: "r"}, + }, + LineEdits: []diff.Edit{{Start: 0, End: 8, New: "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.Edit{{Start: 7, End: 7, New: "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.Edit{{Start: 0, End: 1, New: "B"}}, +}, { + Name: "append_empty", + In: "", // GNU diff -u special case: -0,0 + Out: "AB\nC", + Unified: UnifiedPrefix + ` +@@ -0,0 +1,2 @@ ++AB ++C +\ No newline at end of file +`[1:], + Edits: []diff.Edit{{Start: 0, End: 0, New: "AB\nC"}}, + LineEdits: []diff.Edit{{Start: 0, End: 0, New: "AB\nC"}}, +}, + // TODO(adonovan): fix this test: GNU diff -u prints "+1,2", Unifies prints "+1,3". + // { + // Name: "add_start", + // In: "A", + // Out: "B\nCA", + // Unified: UnifiedPrefix + ` + // @@ -1 +1,2 @@ + // -A + // \ No newline at end of file + // +B + // +CA + // \ No newline at end of file + // `[1:], + // Edits: []diff.TextEdit{{Span: newSpan(0, 0), NewText: "B\nC"}}, + // LineEdits: []diff.TextEdit{{Span: newSpan(0, 0), NewText: "B\nC"}}, + // }, + { + 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.Edit{{Start: 1, End: 1, New: "B"}}, + LineEdits: []diff.Edit{{Start: 0, End: 1, New: "AB"}}, + }, { + Name: "add_empty", + In: "", + Out: "AB\nC", + Unified: UnifiedPrefix + ` +@@ -0,0 +1,2 @@ ++AB ++C +\ No newline at end of file +`[1:], + Edits: []diff.Edit{{Start: 0, End: 0, New: "AB\nC"}}, + LineEdits: []diff.Edit{{Start: 0, End: 0, New: "AB\nC"}}, + }, { + Name: "add_newline", + In: "A", + Out: "A\n", + Unified: UnifiedPrefix + ` +@@ -1 +1 @@ +-A +\ No newline at end of file ++A +`[1:], + Edits: []diff.Edit{{Start: 1, End: 1, New: "\n"}}, + LineEdits: []diff.Edit{{Start: 0, End: 1, New: "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:], + NoDiff: true, // unified diff is different but valid + Edits: []diff.Edit{ + {Start: 0, End: 4, New: ""}, + {Start: 6, End: 6, New: "B\n"}, + {Start: 10, End: 12, New: ""}, + {Start: 14, End: 14, New: "C\n"}, + }, + LineEdits: []diff.Edit{ + {Start: 0, End: 6, New: "C\n"}, + {Start: 6, End: 8, New: "B\nA\n"}, + {Start: 10, End: 14, New: "A\n"}, + {Start: 14, End: 14, New: "C\n"}, + }, + }, { + 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.Edit{{Start: 2, End: 3, New: "C\n"}}, + LineEdits: []diff.Edit{{Start: 2, End: 4, New: "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.Edit{ + {Start: 2, End: 8, New: "H\nI\nJ\n"}, + {Start: 12, End: 14, New: "K\n"}, + }, + NoDiff: true, // diff algorithm produces different delete/insert pattern + }, + { + Name: "extra_newline", + In: "\nA\n", + Out: "A\n", + Edits: []diff.Edit{{Start: 0, End: 1, New: ""}}, + Unified: UnifiedPrefix + `@@ -1,2 +1 @@ +- + A +`, + }, +} + +func DiffTest(t *testing.T, compute func(before, after string) []diff.Edit) { + for _, test := range TestCases { + t.Run(test.Name, func(t *testing.T) { + edits := compute(test.In, test.Out) + got, err := diff.Apply(test.In, edits) + if err != nil { + t.Fatalf("Apply failed: %v", err) + } + unified, err := diff.ToUnified(FileA, FileB, test.In, edits) + if err != nil { + t.Fatalf("ToUnified: %v", err) + } + if got != test.Out { + t.Errorf("Apply: got patched:\n%v\nfrom diff:\n%v\nexpected:\n%v", + got, unified, test.Out) + } + if !test.NoDiff && unified != test.Unified { + t.Errorf("Unified: got diff:\n%q\nexpected:\n%q diffs:%v", + unified, test.Unified, edits) + } + }) + } +} |