Update CI Workflow and Fix Mixed Tab and Space Indentation in Patch File

.github/workflows/ci.yaml

@@ -0,0 +1,28 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 1.20
+          cache: true
+
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Run tests
+        run: go test -v ./...
+
+      - name: Build project
+        run: make build

internal/pkg/patch/patch.go

@@ -1,19 +1,36 @@
 package patch
 
 import (
+	"bufio"
 	"fmt"
 	"os"
 	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strings"
 
 	"github.com/devstream-io/devstream/internal/log"
 )
 
+const (
+	processOptionTabToSpace ProcessOption = "tabToSpace"
+	processOptionSpaceToTab ProcessOption = "spaceToTab"
+)
+
+type ProcessOption string
+
 // Patch calls the patch command to apply a diff file to an original
 func Patch(workDir, patchFile string) error {
 	log.Infof("Patching file: %s", patchFile)
 
+	// Fix patch file if it mixed tab and space indentation
+	err := fixPatchFile(workDir, patchFile)
+	if err != nil {
+		return fmt.Errorf("patch file fix failed: %w", err)
+	}
+
 	// Check if the patch command exists and is executable
-	err := checkPatchCommand()
+	err = checkPatchCommand()
 	if err != nil {
 		return fmt.Errorf("patch command check failed: %w", err)
 	}
@@ -50,3 +67,135 @@ func checkPatchCommand() error {
 
 	return nil
 }
+
+// fixPatchFile fixes the patch file if it mixed tab and space indentation.
+// The patch file is generated by GPT4, and it may have different indentation with the original file.
+// The original file path is contained in the patch file, so we can use the fix the patch file by using the original file.
+// If the original file uses tab indentation, we replace all spaces with tabs in the patch file.
+// If the original file uses space indentation, we replace all tabs with spaces in the patch file.
+func fixPatchFile(workDir, patchFile string) error {
+	// Read the original file path from the patch file
+	originalFilePath, err := extractOriginalFilePathFromPatchFile(patchFile)
+	originalFilePath = filepath.Join(workDir, originalFilePath)
+
+	if err != nil {
+		return fmt.Errorf("failed to extract original file path from patch string: %w", err)
+	}
+
+	// Check if the original file contain tabs in the indentation
+	original, err := os.Open(originalFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to open original file: %w", err)
+	}
+	defer original.Close()
+
+	hasTab := false
+	scanner := bufio.NewScanner(original)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "\t") {
+			hasTab = true
+			break
+		}
+	}
+
+	if err = scanner.Err(); err != nil {
+		return fmt.Errorf("failed to read original file: %w", err)
+	}
+
+	// The original file uses tab indentation
+	if hasTab {
+		// Replace all space indentation with tabs in the patch file
+		if err = processTabSpaceSwitch(patchFile, processOptionSpaceToTab); err != nil {
+			return fmt.Errorf("failed to process tab to space: %w", err)
+		}
+		// The original file uses space indentation
+	} else {
+		// Replace all tab indentation with spaces in the patch file
+		if err = processTabSpaceSwitch(patchFile, processOptionTabToSpace); err != nil {
+			return fmt.Errorf("failed to process space to tab: %w", err)
+		}
+	}
+
+	return nil
+
+}
+
+// ExtractOriginalFilePathFromPatchString extracts the original file path from a patch string
+// e.g. --- pkg/patch/patch.go	2021-08-15 16:00:00.000000000 +0900 -> pkg/patch/patch.go
+func extractOriginalFilePathFromPatchFile(patchFile string) (string, error) {
+	// Read content from the patch file
+	fileContent, err := os.ReadFile(patchFile)
+	if err != nil {
+		return "", fmt.Errorf("failed to read patch file: %w", err)
+	}
+
+	lines := strings.Split(string(fileContent), "\n")
+
+	for _, line := range lines {
+		if strings.HasPrefix(line, "--- ") {
+			fields := strings.Fields(line)
+			if len(fields) > 1 {
+				return fields[1], nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("original file path not found in patch string")
+}
+
+// processTabSpaceSwitch processes the tab/space indentation switch in a file
+// If the option is processOptionTabToSpace, it replaces all tabs with spaces
+// If the option is processOptionSpaceToTab, it replaces all spaces with tabs
+func processTabSpaceSwitch(filePath string, option ProcessOption) error {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	var processedLines []string
+
+	// Matches the start of the string (^) followed by an optional + or - sign, followed by one or more groups of 4 spaces ( {4})+
+	spaceRegex := regexp.MustCompile(`^(\+|\-)?( {4})+`)
+	// Matches the start of the string (^) followed by an optional + or - sign, followed by one or more tabs (\t)+
+	tabRegex := regexp.MustCompile(`^(\+|\-)?\t+`)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if option == processOptionTabToSpace {
+			line = tabRegex.ReplaceAllStringFunc(line, func(s string) string {
+				prefix := ""
+				if s[0] == '+' || s[0] == '-' {
+					prefix = string(s[0])
+					s = s[1:]
+				}
+				return prefix + strings.Repeat("    ", len(s))
+			})
+		} else if option == processOptionSpaceToTab {
+			line = spaceRegex.ReplaceAllStringFunc(line, func(s string) string {
+				prefix := ""
+				if s[0] == '+' || s[0] == '-' {
+					prefix = string(s[0])
+					s = s[1:]
+				}
+				return prefix + strings.Repeat("\t", len(s)/4)
+			})
+		} else {
+			return fmt.Errorf("invalid process option: %s", option)
+		}
+		processedLines = append(processedLines, line)
+	}
+
+	if err = scanner.Err(); err != nil {
+		return fmt.Errorf("failed to read file: %w", err)
+	}
+
+	err = os.WriteFile(filePath, []byte(strings.Join(processedLines, "\n")+"\n"), 0644)
+	if err != nil {
+		return fmt.Errorf("failed to write file: %w", err)
+	}
+
+	return nil
+}

internal/pkg/patch/patch_test.go

@@ -72,32 +72,88 @@ This is the original file.
 			expectedPatchedContent := `Hello, world!
 This is the patched file.
 `
-			Expect(string(patchedContent)).To(Equal(expectedPatchedContent))
+			patchedContentStr := string(patchedContent)
+			Expect(patchedContentStr).To(Equal(expectedPatchedContent))
 		})
 
-		It("returns an error if the patch command is not found or not executable", func() {
-			// Temporarily change PATH to exclude the real patch command
-			originalPath := os.Getenv("PATH")
-			err := os.Setenv("PATH", tempDir)
+		It("returns an error if the patch file is invalid", func() {
+			originalContent := `Hello, world!
+This is the original file.
+`
+
+			err := os.WriteFile(originalFile.Name(), []byte(originalContent), 0644)
+			Expect(err).NotTo(HaveOccurred())
+
+			invalidPatchContent := fmt.Sprintf(`--- %s
++++ new-file
+@@ -1,2 +1,2 @@
+`,
+				filepath.Base(originalFile.Name()))
+
+			err = os.WriteFile(patchFile.Name(), []byte(invalidPatchContent), 0644)
 			Expect(err).NotTo(HaveOccurred())
-			defer func() {
-				err := os.Setenv("PATH", originalPath)
-				Expect(err).NotTo(HaveOccurred())
-			}()
 
 			err = Patch(tempDir, patchFile.Name())
 			Expect(err).To(HaveOccurred())
-			Expect(strings.Contains(err.Error(), "patch command not found")).To(BeTrue())
+			Expect(strings.Contains(err.Error(), "patch command failed")).To(BeTrue())
 		})
+	})
 
-		It("returns an error if the patch file is invalid", func() {
-			invalidPatchContent := `This is not a valid patch file.`
-			err := os.WriteFile(patchFile.Name(), []byte(invalidPatchContent), 0644)
+	Context("when patching a file with inconsistent indentation", func() {
+		It("successfully applies the patch with spaces to the original file with tabs", func() {
+			originalContent := "Hello, world!\n\tThis is the original file with tabs.\n"
+
+			err := os.WriteFile(originalFile.Name(), []byte(originalContent), 0644)
+			Expect(err).NotTo(HaveOccurred())
+
+			patchContent := fmt.Sprintf(`--- %s
++++ new-file
+@@ -1,2 +1,2 @@
+ Hello, world!
+-    This is the original file with tabs.
++    This is the patched file with tabs.
+`,
+				filepath.Base(originalFile.Name()))
+
+			err = os.WriteFile(patchFile.Name(), []byte(patchContent), 0644)
 			Expect(err).NotTo(HaveOccurred())
 
 			err = Patch(tempDir, patchFile.Name())
-			Expect(err).To(HaveOccurred())
-			Expect(strings.Contains(err.Error(), "patch command failed")).To(BeTrue())
+			Expect(err).NotTo(HaveOccurred())
+
+			patchedContent, err := os.ReadFile(originalFile.Name())
+			Expect(err).NotTo(HaveOccurred())
+
+			expectedPatchedContent := "Hello, world!\n\tThis is the patched file with tabs.\n"
+			Expect(string(patchedContent)).To(Equal(expectedPatchedContent))
+		})
+
+		It("successfully applies the patch with tabs to the original file with spaces", func() {
+			originalContent := "Hello, world!\n    This is the original file with spaces.\n"
+
+			err := os.WriteFile(originalFile.Name(), []byte(originalContent), 0644)
+			Expect(err).NotTo(HaveOccurred())
+
+			patchContent := fmt.Sprintf(`--- %s
++++ new-file
+@@ -1,2 +1,2 @@
+ Hello, world!
+-	This is the original file with spaces.
++	This is the patched file with spaces.
+`,
+				filepath.Base(originalFile.Name()))
+
+			err = os.WriteFile(patchFile.Name(), []byte(patchContent), 0644)
+			Expect(err).NotTo(HaveOccurred())
+
+			err = Patch(tempDir, patchFile.Name())
+			Expect(err).NotTo(HaveOccurred())
+
+			patchedContent, err := os.ReadFile(originalFile.Name())
+			Expect(err).NotTo(HaveOccurred())
+
+			expectedPatchedContent := "Hello, world!\n    This is the patched file with spaces.\n"
+			Expect(string(patchedContent)).To(Equal(expectedPatchedContent))
 		})
 	})
 })