willdot.net
patchutil: move patch-related shared code to top-level package
authored by
+121
patchutil/patchutil.go
+121
patchutil/patchutil.go
···
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package patchutil
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import (
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"fmt"
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"regexp"
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"strings"
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"github.com/bluekeyes/go-gitdiff/gitdiff"
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)
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type FormatPatch struct {
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*gitdiff.PatchHeader
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Patch string
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}
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func ExtractPatches(formatPatch string) ([]FormatPatch, error) {
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patches := splitFormatPatch(formatPatch)
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result := []FormatPatch{}
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for _, patch := range patches {
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_, headerStr, err := gitdiff.Parse(strings.NewReader(patch))
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if err != nil {
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return nil, fmt.Errorf("failed to parse patch: %w", err)
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}
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header, err := gitdiff.ParsePatchHeader(headerStr)
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if err != nil {
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return nil, fmt.Errorf("failed to parse patch header: %w", err)
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}
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result = append(result, FormatPatch{
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PatchHeader: header,
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Patch: patch,
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})
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}
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return result, nil
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}
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// Very basic validation to check if it looks like a diff/patch
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// A valid patch usually starts with diff or --- lines or git format-patch header
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func IsPatchValid(patch string) bool {
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// Basic validation to check if it looks like a diff/patch
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// A valid patch usually starts with diff or --- lines
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if len(patch) == 0 {
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return false
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}
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lines := strings.Split(patch, "\n")
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if len(lines) < 2 {
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return false
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}
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// Check for common patch format markers
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firstLine := strings.TrimSpace(lines[0])
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return strings.HasPrefix(firstLine, "diff ") ||
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strings.HasPrefix(firstLine, "--- ") ||
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strings.HasPrefix(firstLine, "Index: ") ||
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strings.HasPrefix(firstLine, "+++ ") ||
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strings.HasPrefix(firstLine, "@@ ") ||
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strings.HasPrefix(firstLine, "From ") && strings.Contains(firstLine, " Mon Sep 17 00:00:00 2001") ||
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strings.HasPrefix(firstLine, "From: ")
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}
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func IsFormatPatch(patch string) bool {
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lines := strings.Split(patch, "\n")
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if len(lines) < 2 {
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return false
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}
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firstLine := strings.TrimSpace(lines[0])
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if strings.HasPrefix(firstLine, "From ") && strings.Contains(firstLine, " Mon Sep 17 00:00:00 2001") {
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return true
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}
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headerCount := 0
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for i := range min(10, len(lines)) {
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line := strings.TrimSpace(lines[i])
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if strings.HasPrefix(line, "From: ") ||
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strings.HasPrefix(line, "Date: ") ||
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strings.HasPrefix(line, "Subject: ") ||
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strings.HasPrefix(line, "commit ") {
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headerCount++
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}
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if strings.HasPrefix(line, "diff --git ") {
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return true
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}
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}
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return headerCount >= 2
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}
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func splitFormatPatch(patchText string) []string {
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// The pattern to match is "From " followed by a commit hash and the rest of that line
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re := regexp.MustCompile(`(?m)^From [0-9a-f]{40} .*$`)
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// Find all starting positions of patches
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indexes := re.FindAllStringIndex(patchText, -1)
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if len(indexes) == 0 {
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// No patches found
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return []string{}
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}
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patches := make([]string, len(indexes))
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for i := range indexes {
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startPos := indexes[i][0]
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endPos := len(patchText)
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// If there's a next patch, set end position to the start of the next patch
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if i < len(indexes)-1 {
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endPos = indexes[i+1][0]
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}
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// Extract the patch and trim any whitespace
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patches[i] = strings.TrimSpace(patchText[startPos:endPos])
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}
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return patches
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}
+210
patchutil/patchutil_test.go
+210
patchutil/patchutil_test.go
···
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package patchutil
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import (
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"reflect"
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"testing"
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)
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func TestSplitPatches(t *testing.T) {
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tests := []struct {
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name string
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input string
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expected []string
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}{
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{
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name: "Empty input",
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input: "",
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expected: []string{},
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},
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{
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name: "No valid patches",
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input: "This is not a patch\nJust some random text",
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expected: []string{},
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},
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{
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name: "Single patch",
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input: `From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:01:00 +0300
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Subject: [PATCH] Example patch
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diff --git a/file.txt b/file.txt
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index 123456..789012 100644
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--- a/file.txt
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+++ b/file.txt
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@@ -1 +1 @@
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-old content
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+new content
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--
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2.48.1`,
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expected: []string{
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`From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:01:00 +0300
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Subject: [PATCH] Example patch
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diff --git a/file.txt b/file.txt
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index 123456..789012 100644
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--- a/file.txt
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+++ b/file.txt
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@@ -1 +1 @@
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-old content
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+new content
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--
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2.48.1`,
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},
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},
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{
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name: "Two patches",
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input: `From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:01:00 +0300
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Subject: [PATCH 1/2] First patch
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diff --git a/file1.txt b/file1.txt
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index 123456..789012 100644
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--- a/file1.txt
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+++ b/file1.txt
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@@ -1 +1 @@
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-old content
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+new content
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--
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2.48.1
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From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:03:11 +0300
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Subject: [PATCH 2/2] Second patch
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diff --git a/file2.txt b/file2.txt
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index abcdef..ghijkl 100644
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--- a/file2.txt
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+++ b/file2.txt
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@@ -1 +1 @@
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-foo bar
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+baz qux
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--
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2.48.1`,
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expected: []string{
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`From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:01:00 +0300
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Subject: [PATCH 1/2] First patch
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diff --git a/file1.txt b/file1.txt
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index 123456..789012 100644
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--- a/file1.txt
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+++ b/file1.txt
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@@ -1 +1 @@
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-old content
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+new content
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--
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2.48.1`,
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`From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Date: Wed, 16 Apr 2025 11:03:11 +0300
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Subject: [PATCH 2/2] Second patch
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diff --git a/file2.txt b/file2.txt
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index abcdef..ghijkl 100644
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--- a/file2.txt
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+++ b/file2.txt
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@@ -1 +1 @@
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-foo bar
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+baz qux
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--
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2.48.1`,
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},
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},
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{
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name: "Patches with additional text between them",
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input: `Some text before the patches
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From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: [PATCH] First patch
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diff content here
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--
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2.48.1
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Some text between patches
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From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: [PATCH] Second patch
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more diff content
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--
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2.48.1
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Text after patches`,
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expected: []string{
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`From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: [PATCH] First patch
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diff content here
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--
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2.48.1
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Some text between patches`,
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`From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: [PATCH] Second patch
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more diff content
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--
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2.48.1
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Text after patches`,
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},
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},
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{
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name: "Patches with whitespace padding",
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input: `
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From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: Patch
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170
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content
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--
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2.48.1
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From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: Another patch
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179
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content
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--
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2.48.1
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`,
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expected: []string{
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`From 3c5035488318164b81f60fe3adcd6c9199d76331 Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: Patch
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188
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content
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--
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2.48.1`,
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`From a9529f3b3a653329a5268f0f4067225480207e3c Mon Sep 17 00:00:00 2001
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From: Author <author@example.com>
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Subject: Another patch
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195
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content
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--
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2.48.1`,
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},
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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result := splitFormatPatch(tt.input)
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if !reflect.DeepEqual(result, tt.expected) {
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t.Errorf("splitPatches() = %v, want %v", result, tt.expected)
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}
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})
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}
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}