03ad5a8 fix(diff): count only changed lines against the diff line limits · ermite

M internal/adapters/gitcli/diff.go +7 -4


@@ -379,7 +379,7 @@ func (p *patchReader) skip(n int) error {
379	379		}
380	380
381	381		// file reads the sections of one file and returns its hunks, the number of
382		-	// hunk lines, and whether it exceeded max lines or had a line over
	382	+	// changed lines, and whether it exceeded max changed lines or had a line over
383	383		// maxDiffLine. When truncated, the rest of the file is skipped.
384	384		func (p *patchReader) file(sections, max int) (hunks []domain.Hunk, lines int, truncated bool, err error) {
385	385		for done := range sections {

@@ -405,7 +405,7 @@ func (p *patchReader) file(sections, max int) (hunks []domain.Hunk, lines int, t
405	405		}
406	406
407	407		// section reads the hunks of the current section up to the next marker, which
408		-	// stays pending. It gives up (truncated) after more than max lines.
	408	+	// stays pending. It gives up (truncated) after more than max changed lines.
409	409		func (p *patchReader) section(max int) (hunks []domain.Hunk, lines int, truncated bool, err error) {
410	410		var cur *domain.Hunk
411	411		var oldN, newN int

@@ -459,8 +459,11 @@ func (p *patchReader) section(max int) (hunks []domain.Hunk, lines int, truncate
459	459		default:
460	460		continue
461	461		}
462		-	lines++
463		-	fits := p.budget.ChargeLine(len(text))
	462	+	changed := l.Kind == domain.LineAddition \|\| l.Kind == domain.LineDeletion
	463	+	if changed {
	464	+	lines++
	465	+	}
	466	+	fits := p.budget.ChargeLine(len(text), changed)
464	467		if lines > max \|\| !fits {
465	468		return nil, lines, true, nil
466	469		}

 }
 // file reads the sections of one file and returns its hunks, the number of
-// hunk lines, and whether it exceeded max lines or had a line over
+// changed lines, and whether it exceeded max changed lines or had a line over
 // maxDiffLine. When truncated, the rest of the file is skipped.
 func (p *patchReader) file(sections, max int) (hunks []domain.Hunk, lines int, truncated bool, err error) {
 	for done := range sections {
 }
 // section reads the hunks of the current section up to the next marker, which
-// stays pending. It gives up (truncated) after more than max lines.
+// stays pending. It gives up (truncated) after more than max changed lines.
 func (p *patchReader) section(max int) (hunks []domain.Hunk, lines int, truncated bool, err error) {
 	var cur *domain.Hunk
 	var oldN, newN int
 		default:
 			continue
 		}
-		lines++
+		changed := l.Kind == domain.LineAddition || l.Kind == domain.LineDeletion
-		fits := p.budget.ChargeLine(len(text))
+		if changed {
+			lines++
+		}
+		fits := p.budget.ChargeLine(len(text), changed)
 		if lines > max || !fits {
 			return nil, lines, true, nil
 		}

M internal/adapters/gitcli/diff_test.go +15 -5


@@ -13,6 +13,7 @@ import (
13	13		"github.com/stretchr/testify/require"
14	14
15	15		"bnema.dev/ermite/internal/domain"
	16	+	"bnema.dev/ermite/internal/ports"
16	17		"bnema.dev/ermite/internal/readertest"
17	18		)
18	19

@@ -327,10 +328,10 @@ func TestDiffLimits(t *testing.T) {
327	328		assert.Equal(t, domain.DiffStats{FilesChanged: 3, Additions: 4004}, d.Stats)
328	329		})
329	330
330		-	t.Run("context counts towards the file limit", func(t *testing.T) {
	331	+	t.Run("context does not count towards the file limit", func(t *testing.T) {
331	332		f := readertest.NewFixture(t, data, "limit-context")
332	333		f.Lines("big", "l", 3000).Commit("v1")
333		-	// Every 7th line changes: ~428 changed lines, but the hunks merge
	334	+	// Every 7th line changes: 429 additions plus 429 deletions, but the hunks merge
334	335		// into one that spans the file with its context.
335	336		var b strings.Builder
336	337		for i := range 3000 {

@@ -346,11 +347,13 @@ func TestDiffLimits(t *testing.T) {
346	347		d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
347	348		require.NoError(t, err)
348	349		big, tiny := find(d.Diff, "big"), find(d.Diff, "tiny")
349		-	assert.True(t, big.Truncated)
350		-	assert.Empty(t, big.Hunks)
	350	+	assert.False(t, big.Truncated)
	351	+	require.Len(t, big.Hunks, 1)
	352	+	assert.Len(t, big.Hunks[0].Lines, 3000+429)
	353	+	assert.False(t, d.Diff.Truncated)
351	354		assert.Equal(t, 429, big.Additions)
352	355		assert.Equal(t, 429, big.Deletions)
353		-	assert.False(t, tiny.Truncated, "the file after a truncated one is still read")
	356	+	assert.False(t, tiny.Truncated, "the following file still fits the changed-line budget")
354	357		assert.Equal(t, "x\n", strings.TrimPrefix(unified(tiny.Hunks), "@@ -0,0 +1 @@\n+"))
355	358		assert.Equal(t, id, d.Commit.ID.String())
356	359		})

@@ -660,3 +663,10 @@ func TestDiffLimitsWindow(t *testing.T) {
660	663		assert.True(t, d.Diff.Truncated)
661	664		})
662	665		}
	666	+
	667	+	func TestDiffChangedLineLimits(t *testing.T) {
	668	+	readertest.DiffChangedLineLimits(t, func(t *testing.T) (ports.RepoReader, string) {
	669	+	g, data := newReader(t, nil)
	670	+	return g, data
	671	+	})
	672	+	}

 	"github.com/stretchr/testify/require"
 	"bnema.dev/ermite/internal/domain"
+	"bnema.dev/ermite/internal/ports"
 	"bnema.dev/ermite/internal/readertest"
 )
 		assert.Equal(t, domain.DiffStats{FilesChanged: 3, Additions: 4004}, d.Stats)
 	})
-	t.Run("context counts towards the file limit", func(t *testing.T) {
+	t.Run("context does not count towards the file limit", func(t *testing.T) {
 		f := readertest.NewFixture(t, data, "limit-context")
 		f.Lines("big", "l", 3000).Commit("v1")
-		// Every 7th line changes: ~428 changed lines, but the hunks merge
+		// Every 7th line changes: 429 additions plus 429 deletions, but the hunks merge
 		// into one that spans the file with its context.
 		var b strings.Builder
 		for i := range 3000 {
 		d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
 		require.NoError(t, err)
 		big, tiny := find(d.Diff, "big"), find(d.Diff, "tiny")
-		assert.True(t, big.Truncated)
+		assert.False(t, big.Truncated)
-		assert.Empty(t, big.Hunks)
+		require.Len(t, big.Hunks, 1)
+		assert.Len(t, big.Hunks[0].Lines, 3000+429)
+		assert.False(t, d.Diff.Truncated)
 		assert.Equal(t, 429, big.Additions)
 		assert.Equal(t, 429, big.Deletions)
-		assert.False(t, tiny.Truncated, "the file after a truncated one is still read")
+		assert.False(t, tiny.Truncated, "the following file still fits the changed-line budget")
 		assert.Equal(t, "x\n", strings.TrimPrefix(unified(tiny.Hunks), "@@ -0,0 +1 @@\n+"))
 		assert.Equal(t, id, d.Commit.ID.String())
 	})
 		assert.True(t, d.Diff.Truncated)
 	})
 }
+func TestDiffChangedLineLimits(t *testing.T) {
+	readertest.DiffChangedLineLimits(t, func(t *testing.T) (ports.RepoReader, string) {
+		g, data := newReader(t, nil)
+		return g, data
+	})
+}

M internal/adapters/web/diff_highlight.go +1 -1


@@ -48,7 +48,7 @@ var maxDiffHLTotalBytes = 256 << 10
48	48
49	49		const (
50	50		// maxDiffHLFileBytes is the most text of one file of a diff that is
51		-	// lexed. The diff limits (domain.DefaultDiffLimits) allow 2,000 lines a
	51	+	// lexed. The diff limits (domain.DefaultDiffLimits) allow 2,000 changed lines a
52	52		// file; this keeps a file of very long lines out.
53	53		maxDiffHLFileBytes = 128 << 10
54	54		// maxDiffHLLine is the longest line that is lexed, in bytes: a minified


@@ -48,7 +48,7 @@ var maxDiffHLTotalBytes = 256 << 10
48			48
49		const (	49		const (
50		// maxDiffHLFileBytes is the most text of one file of a diff that is	50		// maxDiffHLFileBytes is the most text of one file of a diff that is
51	-	// lexed. The diff limits (domain.DefaultDiffLimits) allow 2,000 lines a	51	+	// lexed. The diff limits (domain.DefaultDiffLimits) allow 2,000 changed lines a
52		// file; this keeps a file of very long lines out.	52		// file; this keeps a file of very long lines out.
53		maxDiffHLFileBytes = 128 << 10	53		maxDiffHLFileBytes = 128 << 10
54		// maxDiffHLLine is the longest line that is lexed, in bytes: a minified	54		// maxDiffHLLine is the longest line that is lexed, in bytes: a minified

M internal/adapters/web/diff_highlight_test.go +1 -1


@@ -273,7 +273,7 @@ func goSource(n int) []string {
273	273		}
274	274
275	275		// largeDiff is n files of 1,000 lines of Go with 250 lines changed in place
276		-	// and 250 added, 1,500 lines a file (the limit of the diffs is 2,000 lines a
	276	+	// and 250 added, 1,500 lines a file (the limit of the diffs is 2,000 changed lines a
277	277		// file and 20,000 in all, domain.DefaultDiffLimits); a file is about 36 KB.
278	278		func largeDiff(n int) []domain.FileDiff {
279	279		var files []domain.FileDiff


@@ -273,7 +273,7 @@ func goSource(n int) []string {
273		}	273		}
274			274
275		// largeDiff is n files of 1,000 lines of Go with 250 lines changed in place	275		// largeDiff is n files of 1,000 lines of Go with 250 lines changed in place
276	-	// and 250 added, 1,500 lines a file (the limit of the diffs is 2,000 lines a	276	+	// and 250 added, 1,500 lines a file (the limit of the diffs is 2,000 changed lines a
277		// file and 20,000 in all, domain.DefaultDiffLimits); a file is about 36 KB.	277		// file and 20,000 in all, domain.DefaultDiffLimits); a file is about 36 KB.
278		func largeDiff(n int) []domain.FileDiff {	278		func largeDiff(n int) []domain.FileDiff {
279		var files []domain.FileDiff	279		var files []domain.FileDiff

M internal/domain/budget.go +6 -3


@@ -77,9 +77,12 @@ func (b DiffBudget) WantsHunks(binary bool, n int) bool {
77	77
78	78		func (b DiffBudget) FileLines() int { return min(b.limits.MaxFileLines, b.linesLeft) }
79	79
80		-	// ChargeLine accounts for one decoded hunk line and reports whether it fits.
81		-	func (b *DiffBudget) ChargeLine(bytes int) bool {
82		-	b.linesLeft--
	80	+	// ChargeLine accounts for decoded text bytes and, for additions or deletions,
	81	+	// one changed line. Context consumes bytes only. It reports whether the line fits.
	82	+	func (b *DiffBudget) ChargeLine(bytes int, changed bool) bool {
	83	+	if changed {
	84	+	b.linesLeft--
	85	+	}
83	86		b.bytesLeft -= bytes
84	87		return b.linesLeft >= 0 && b.bytesLeft >= 0
85	88		}

 func (b DiffBudget) FileLines() int { return min(b.limits.MaxFileLines, b.linesLeft) }
-// ChargeLine accounts for one decoded hunk line and reports whether it fits.
+// ChargeLine accounts for decoded text bytes and, for additions or deletions,
-func (b *DiffBudget) ChargeLine(bytes int) bool {
+// one changed line. Context consumes bytes only. It reports whether the line fits.
-	b.linesLeft--
+func (b *DiffBudget) ChargeLine(bytes int, changed bool) bool {
+	if changed {
+		b.linesLeft--
+	}
 	b.bytesLeft -= bytes
 	return b.linesLeft >= 0 && b.bytesLeft >= 0
 }

M internal/domain/budget_test.go +18 -2


@@ -126,10 +126,10 @@ func TestDiffBudgetCharge(t *testing.T) {
126	126		if b.FileLines() != 1 {
127	127		t.Fatal("wrong file limit")
128	128		}
129		-	if b.ChargeLine(tt.bytes) != tt.fits {
	129	+	if b.ChargeLine(tt.bytes, true) != tt.fits {
130	130		t.Fatal("wrong charge result")
131	131		}
132		-	if b.ChargeLine(0) {
	132	+	if b.ChargeLine(0, true) {
133	133		t.Fatal("line budget exceeded")
134	134		}
135	135		b = before

@@ -139,3 +139,19 @@ func TestDiffBudgetCharge(t *testing.T) {
139	139		})
140	140		}
141	141		}
	142	+
	143	+	func TestDiffBudgetContext(t *testing.T) {
	144	+	b := NewDiffBudget(DiffLimits{MaxFileLines: 2, MaxTotalLines: 2, MaxTotalBytes: 6})
	145	+	if !b.ChargeLine(2, false) \|\| b.FileLines() != 2 {
	146	+	t.Fatal("context consumed changed-line budget")
	147	+	}
	148	+	if !b.ChargeLine(1, true) \|\| !b.ChargeLine(1, true) \|\| b.FileLines() != 0 {
	149	+	t.Fatal("additions and deletions must consume changed-line budget")
	150	+	}
	151	+	if !b.ChargeLine(2, false) {
	152	+	t.Fatal("context at the byte boundary must fit even without changed lines left")
	153	+	}
	154	+	if b.ChargeLine(1, false) {
	155	+	t.Fatal("context must not exceed the byte budget")
	156	+	}
	157	+	}


@@ -126,10 +126,10 @@ func TestDiffBudgetCharge(t *testing.T) {
126		if b.FileLines() != 1 {	126		if b.FileLines() != 1 {
127		t.Fatal("wrong file limit")	127		t.Fatal("wrong file limit")
128		}	128		}
129	-	if b.ChargeLine(tt.bytes) != tt.fits {	129	+	if b.ChargeLine(tt.bytes, true) != tt.fits {
130		t.Fatal("wrong charge result")	130		t.Fatal("wrong charge result")
131		}	131		}
132	-	if b.ChargeLine(0) {	132	+	if b.ChargeLine(0, true) {
133		t.Fatal("line budget exceeded")	133		t.Fatal("line budget exceeded")
134		}	134		}
135		b = before	135		b = before

@@ -139,3 +139,19 @@ func TestDiffBudgetCharge(t *testing.T) {
139		})	139		})
140		}	140		}
141		}	141		}
			142	+
			143	+	func TestDiffBudgetContext(t *testing.T) {
			144	+	b := NewDiffBudget(DiffLimits{MaxFileLines: 2, MaxTotalLines: 2, MaxTotalBytes: 6})
			145	+	if !b.ChargeLine(2, false) \|\| b.FileLines() != 2 {
			146	+	t.Fatal("context consumed changed-line budget")
			147	+	}
			148	+	if !b.ChargeLine(1, true) \|\| !b.ChargeLine(1, true) \|\| b.FileLines() != 0 {
			149	+	t.Fatal("additions and deletions must consume changed-line budget")
			150	+	}
			151	+	if !b.ChargeLine(2, false) {
			152	+	t.Fatal("context at the byte boundary must fit even without changed lines left")
			153	+	}
			154	+	if b.ChargeLine(1, false) {
			155	+	t.Fatal("context must not exceed the byte budget")
			156	+	}
			157	+	}

M internal/domain/git.go +6 -5


@@ -537,19 +537,19 @@ type CommitDetail struct {
537	537		Diff Diff
538	538		}
539	539
540		-	// DiffLimits bound the size of a Diff. Lines are hunk lines, context included.
	540	+	// DiffLimits bound the size of a Diff. Line limits count additions plus deletions, not context.
541	541		type DiffLimits struct {
542	542		// MaxFiles is the number of files kept; 0 means no limit on the number of
543	543		// files (every changed file is listed).
544	544		MaxFiles int
545		-	// MaxFileLines is the most lines one file may have; a file over it is
	545	+	// MaxFileLines is the most changed lines one file may have; a file over it is
546	546		// truncated.
547	547		MaxFileLines int
548		-	// MaxTotalLines is the most lines of all the files. A file is truncated
	548	+	// MaxTotalLines is the most changed lines of all the files. A file is truncated
549	549		// when it does not fit in what remains; a smaller one after it may still
550	550		// fit.
551	551		MaxTotalLines int
552		-	// MaxTotalBytes is the most text, in bytes, of all the lines. It bounds
	552	+	// MaxTotalBytes is the most text, in bytes, of all the lines, including context. It bounds
553	553		// the memory of a diff whose lines are very long; files are truncated
554	554		// like for MaxTotalLines.
555	555		MaxTotalBytes int

@@ -563,7 +563,8 @@ type DiffLimits struct {
563	563		}
564	564
565	565		// DefaultDiffLimits are the limits of the API contract: 300 files, 2,000
566		-	// lines per file, 20,000 lines in total, plus 8 MiB of text.
	566	+	// changed lines per file, 20,000 changed lines in total, plus 8 MiB of text
	567	+	// including context.
567	568		func DefaultDiffLimits() DiffLimits {
568	569		return DiffLimits{MaxFiles: 300, MaxFileLines: 2000, MaxTotalLines: 20000, MaxTotalBytes: 8 << 20}
569	570		}

 	Diff   Diff
 }
-// DiffLimits bound the size of a Diff. Lines are hunk lines, context included.
+// DiffLimits bound the size of a Diff. Line limits count additions plus deletions, not context.
 type DiffLimits struct {
 	// MaxFiles is the number of files kept; 0 means no limit on the number of
 	// files (every changed file is listed).
 	MaxFiles int
-	// MaxFileLines is the most lines one file may have; a file over it is
+	// MaxFileLines is the most changed lines one file may have; a file over it is
 	// truncated.
 	MaxFileLines int
-	// MaxTotalLines is the most lines of all the files. A file is truncated
+	// MaxTotalLines is the most changed lines of all the files. A file is truncated
 	// when it does not fit in what remains; a smaller one after it may still
 	// fit.
 	MaxTotalLines int
-	// MaxTotalBytes is the most text, in bytes, of all the lines. It bounds
+	// MaxTotalBytes is the most text, in bytes, of all the lines, including context. It bounds
 	// the memory of a diff whose lines are very long; files are truncated
 	// like for MaxTotalLines.
 	MaxTotalBytes int
 }
 // DefaultDiffLimits are the limits of the API contract: 300 files, 2,000
-// lines per file, 20,000 lines in total, plus 8 MiB of text.
+// changed lines per file, 20,000 changed lines in total, plus 8 MiB of text
+// including context.
 func DefaultDiffLimits() DiffLimits {
 	return DiffLimits{MaxFiles: 300, MaxFileLines: 2000, MaxTotalLines: 20000, MaxTotalBytes: 8 << 20}
 }

M internal/readertest/conformance.go +1 -0


@@ -31,6 +31,7 @@ func Conformance(t *testing.T, mk Maker) {
31	31		name string
32	32		fn func(*testing.T, Maker)
33	33		}{
	34	+	{"DiffChangedLineLimits", DiffChangedLineLimits},
34	35		{"ListRefs", testListRefs},
35	36		{"ListRefsEmptyAndMissing", testListRefsEmptyAndMissing},
36	37		{"DetachedHead", testDetachedHead},


@@ -31,6 +31,7 @@ func Conformance(t *testing.T, mk Maker) {
31	name string	31		name string
32	fn func(*testing.T, Maker)	32		fn func(*testing.T, Maker)
33	}{	33		}{
		34	+	{"DiffChangedLineLimits", DiffChangedLineLimits},
34	{"ListRefs", testListRefs},	35		{"ListRefs", testListRefs},
35	{"ListRefsEmptyAndMissing", testListRefsEmptyAndMissing},	36		{"ListRefsEmptyAndMissing", testListRefsEmptyAndMissing},
36	{"DetachedHead", testDetachedHead},	37		{"DetachedHead", testDetachedHead},

A internal/readertest/diff.go +70 -0

@@ -0,0 +1,70 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package readertest
	4	+
	5	+	import (
	6	+	"context"
	7	+	"fmt"
	8	+	"strings"
	9	+	"testing"
	10	+
	11	+	"github.com/stretchr/testify/assert"
	12	+	"github.com/stretchr/testify/require"
	13	+
	14	+	"bnema.dev/ermite/internal/domain"
	15	+	)
	16	+
	17	+	// DiffChangedLineLimits checks that context is retained without consuming the
	18	+	// changed-line limits, but still consumes the byte budget.
	19	+	func DiffChangedLineLimits(t *testing.T, mk Maker) {
	20	+	g, data := mk(t)
	21	+	f := NewFixture(t, data, "diff-context-budget")
	22	+	var before, after strings.Builder
	23	+	const hunks = 96
	24	+	for i := range hunks * 10 {
	25	+	line := fmt.Sprintf("context %04d", i)
	26	+	fmt.Fprintln(&before, line)
	27	+	if i%10 == 4 {
	28	+	line = fmt.Sprintf("changed %04d", i)
	29	+	}
	30	+	fmt.Fprintln(&after, line)
	31	+	}
	32	+	f.Write("many", before.String()).Commit("before")
	33	+	f.Write("many", after.String()).Commit("after")
	34	+	limits := domain.DiffLimits{MaxFileLines: hunks * 2, MaxTotalLines: hunks * 2, MaxTotalBytes: 1 << 20}
	35	+	d, err := g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	36	+	require.NoError(t, err)
	37	+	require.Len(t, d.Diff.Files, 1)
	38	+	file := d.Diff.Files[0]
	39	+	require.False(t, file.Truncated)
	40	+	assert.False(t, d.Diff.Truncated)
	41	+	require.Len(t, file.Hunks, hunks)
	42	+	var changed, patchLines, textBytes, changedBytes int
	43	+	for _, h := range file.Hunks {
	44	+	for _, l := range h.Lines {
	45	+	patchLines++
	46	+	textBytes += len(l.Text)
	47	+	if l.Kind != domain.LineContext {
	48	+	changed++
	49	+	changedBytes += len(l.Text)
	50	+	}
	51	+	}
	52	+	}
	53	+	assert.Equal(t, hunks*2, changed)
	54	+	assert.Greater(t, patchLines, limits.MaxFileLines)
	55	+	assert.Equal(t, hunks, file.Additions)
	56	+	assert.Equal(t, hunks, file.Deletions)
	57	+	// The exact byte boundary fits; one fewer byte must discard the file even
	58	+	// though every changed line's text alone easily fits.
	59	+	limits.MaxTotalBytes = textBytes
	60	+	d, err = g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	61	+	require.NoError(t, err)
	62	+	assert.False(t, d.Diff.Files[0].Truncated)
	63	+	limits.MaxTotalBytes--
	64	+	require.Greater(t, limits.MaxTotalBytes, changedBytes)
	65	+	d, err = g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	66	+	require.NoError(t, err)
	67	+	assert.True(t, d.Diff.Truncated)
	68	+	assert.True(t, d.Diff.Files[0].Truncated)
	69	+	assert.Empty(t, d.Diff.Files[0].Hunks)
	70	+	}

@@ -0,0 +1,70 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package readertest
	4	+
	5	+	import (
	6	+	"context"
	7	+	"fmt"
	8	+	"strings"
	9	+	"testing"
	10	+
	11	+	"github.com/stretchr/testify/assert"
	12	+	"github.com/stretchr/testify/require"
	13	+
	14	+	"bnema.dev/ermite/internal/domain"
	15	+	)
	16	+
	17	+	// DiffChangedLineLimits checks that context is retained without consuming the
	18	+	// changed-line limits, but still consumes the byte budget.
	19	+	func DiffChangedLineLimits(t *testing.T, mk Maker) {
	20	+	g, data := mk(t)
	21	+	f := NewFixture(t, data, "diff-context-budget")
	22	+	var before, after strings.Builder
	23	+	const hunks = 96
	24	+	for i := range hunks * 10 {
	25	+	line := fmt.Sprintf("context %04d", i)
	26	+	fmt.Fprintln(&before, line)
	27	+	if i%10 == 4 {
	28	+	line = fmt.Sprintf("changed %04d", i)
	29	+	}
	30	+	fmt.Fprintln(&after, line)
	31	+	}
	32	+	f.Write("many", before.String()).Commit("before")
	33	+	f.Write("many", after.String()).Commit("after")
	34	+	limits := domain.DiffLimits{MaxFileLines: hunks * 2, MaxTotalLines: hunks * 2, MaxTotalBytes: 1 << 20}
	35	+	d, err := g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	36	+	require.NoError(t, err)
	37	+	require.Len(t, d.Diff.Files, 1)
	38	+	file := d.Diff.Files[0]
	39	+	require.False(t, file.Truncated)
	40	+	assert.False(t, d.Diff.Truncated)
	41	+	require.Len(t, file.Hunks, hunks)
	42	+	var changed, patchLines, textBytes, changedBytes int
	43	+	for _, h := range file.Hunks {
	44	+	for _, l := range h.Lines {
	45	+	patchLines++
	46	+	textBytes += len(l.Text)
	47	+	if l.Kind != domain.LineContext {
	48	+	changed++
	49	+	changedBytes += len(l.Text)
	50	+	}
	51	+	}
	52	+	}
	53	+	assert.Equal(t, hunks*2, changed)
	54	+	assert.Greater(t, patchLines, limits.MaxFileLines)
	55	+	assert.Equal(t, hunks, file.Additions)
	56	+	assert.Equal(t, hunks, file.Deletions)
	57	+	// The exact byte boundary fits; one fewer byte must discard the file even
	58	+	// though every changed line's text alone easily fits.
	59	+	limits.MaxTotalBytes = textBytes
	60	+	d, err = g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	61	+	require.NoError(t, err)
	62	+	assert.False(t, d.Diff.Files[0].Truncated)
	63	+	limits.MaxTotalBytes--
	64	+	require.Greater(t, limits.MaxTotalBytes, changedBytes)
	65	+	d, err = g.GetCommit(context.Background(), f.Name, domain.Revision{}, limits)
	66	+	require.NoError(t, err)
	67	+	assert.True(t, d.Diff.Truncated)
	68	+	assert.True(t, d.Diff.Files[0].Truncated)
	69	+	assert.Empty(t, d.Diff.Files[0].Hunks)
	70	+	}