ladybird/Tests/LibDiff/TestDiff.cpp
Shannon Booth b738929195 LibDiff: Fix wrong index used when prepending context lines
`i` is used as the index for 'old lines' in diff generation, not 'new
lines'. Using the wrong index would mean that for certain diffs the
prefixed context information would have wrong content, and could even
result in a crash.

Fix this, and add a test for an input which was previously crashing.
2023-09-11 12:10:50 +01:00

109 lines
4.6 KiB
C++

/*
* Copyright (c) 2023, Shannon Booth <shannon@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/MemoryStream.h>
#include <LibDiff/Format.h>
#include <LibDiff/Generator.h>
#include <LibTest/TestCase.h>
TEST_CASE(test_generate_unified_diff)
{
StringView old_text = R"(Viewport <#document> at (0,0) content-size 800x600 children: not-inline
BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
BlockContainer <body> at (8,8) content-size 784x150 children: not-inline
BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
TextNode <#text>
TextNode <#text>
BlockContainer <div> at (8,8) content-size 784x150 children: inline
line 0 width: 300, height: 150, bottom: 150, baseline: 150
frag 0 from SVGSVGBox start: 0, length: 0, rect: [8,8 300x150]
TextNode <#text>
SVGSVGBox <svg> at (8,8) content-size 300x150 [SVG] children: inline
TextNode <#text>
Box <use> at (8,8) content-size 0x0 children: inline
Box <symbol#braces> at (8,8) content-size 0x0 children: inline
TextNode <#text>
SVGGeometryBox <path> at (92.375,26.75) content-size 131.25x112.15625 children: inline
TextNode <#text>
TextNode <#text>
TextNode <#text>
TextNode <#text>
ViewportPaintable (Viewport<#document>) [0,0 800x600]
PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
PaintableWithLines (BlockContainer<BODY>) [8,8 784x150]
PaintableWithLines (BlockContainer(anonymous)) [8,8 784x0]
PaintableWithLines (BlockContainer<DIV>) [8,8 784x150]
SVGSVGPaintable (SVGSVGBox<svg>) [8,8 300x150]
PaintableBox (Box<use>) [8,8 0x0]
PaintableBox (Box<symbol>#braces) [8,8 0x0]
SVGGeometryPaintable (SVGGeometryBox<path>) [92.375,26.75 131.25x112.15625]
)"sv;
StringView new_text = R"(Viewport <#document> at (0,0) content-size 800x600 children: not-inline
BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
BlockContainer <body> at (8,8) content-size 784x150 children: not-inline
BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
TextNode <#text>
TextNode <#text>
BlockContainer <div> at (8,8) content-size 784x150 children: inline
line 0 width: 300, height: 150, bottom: 150, baseline: 150
frag 0 from SVGSVGBox start: 0, length: 0, rect: [8,8 300x150]
TextNode <#text>
SVGSVGBox <svg> at (8,8) content-size 300x150 [SVG] children: inline
TextNode <#text>
Box <use> at (8,8) content-size 0x0 children: not-inline
TextNode <#text>
TextNode <#text>
ViewportPaintable (Viewport<#document>) [0,0 800x600]
PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
PaintableWithLines (BlockContainer<BODY>) [8,8 784x150]
PaintableWithLines (BlockContainer(anonymous)) [8,8 784x0]
PaintableWithLines (BlockContainer<DIV>) [8,8 784x150]
SVGSVGPaintable (SVGSVGBox<svg>) [8,8 300x150]
PaintableBox (Box<use>) [8,8 0x0]
)"sv;
auto result = MUST(Diff::from_text(old_text, new_text, 3));
EXPECT_EQ(result.size(), 2U);
auto hunk1_stream = make<AllocatingMemoryStream>();
MUST(Diff::write_unified(result[0], *hunk1_stream));
auto hunk1 = MUST(hunk1_stream->read_until_eof());
EXPECT_EQ(StringView { hunk1 }, R"(@@ -10,12 +10,7 @@
TextNode <#text>
SVGSVGBox <svg> at (8,8) content-size 300x150 [SVG] children: inline
TextNode <#text>
- Box <use> at (8,8) content-size 0x0 children: inline
- Box <symbol#braces> at (8,8) content-size 0x0 children: inline
- TextNode <#text>
- SVGGeometryBox <path> at (92.375,26.75) content-size 131.25x112.15625 children: inline
- TextNode <#text>
- TextNode <#text>
+ Box <use> at (8,8) content-size 0x0 children: not-inline
TextNode <#text>
TextNode <#text>
)"sv);
auto hunk2_stream = make<AllocatingMemoryStream>();
MUST(Diff::write_unified(result[1], *hunk2_stream));
auto hunk2 = MUST(hunk2_stream->read_until_eof());
EXPECT_EQ(StringView { hunk2 }, R"(@@ -26,6 +21,4 @@
PaintableWithLines (BlockContainer<DIV>) [8,8 784x150]
SVGSVGPaintable (SVGSVGBox<svg>) [8,8 300x150]
PaintableBox (Box<use>) [8,8 0x0]
- PaintableBox (Box<symbol>#braces) [8,8 0x0]
- SVGGeometryPaintable (SVGGeometryBox<path>) [92.375,26.75 131.25x112.15625]
)"sv);
}