adjust indent position

gnoverse · Sep 27, 2024 · 3b69244 · 3b69244
1 parent 64fa7f8
commit 3b69244
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Showing 3 changed files with 145 additions and 36 deletions.
diff --git a/formatter/builder.go b/formatter/builder.go
@@ -35,6 +35,8 @@ var (
 
 // IssueFormatter is the interface that wraps the Format method.
 // Implementations of this interface are responsible for formatting specific types of lint issues.
+//
+// ! TODO: Use template to format issue
 type IssueFormatter interface {
 	Format(issue tt.Issue, snippet *internal.SourceCode) string
 }
@@ -128,17 +130,24 @@ func (b *IssueFormatterBuilder) AddCodeSnippet() *IssueFormatterBuilder {
 	endLine := b.issue.End.Line
 	maxLineNumWidth := calculateMaxLineNumWidth(endLine)
 
+	var commonIndent string
+	if startLine-1 < 0 || endLine > len(b.snippet.Lines) || startLine > endLine {
+		commonIndent = ""
+	} else {
+		commonIndent = findCommonIndent(b.snippet.Lines[startLine-1 : endLine])
+	}
+
 	// add separator
 	padding := strings.Repeat(" ", maxLineNumWidth+1)
 	b.result.WriteString(lineStyle.Sprintf("%s|\n", padding))
 
 	for i := startLine; i <= endLine; i++ {
-		// check that the line number does not go out of range of snippet.Lines
 		if i-1 < 0 || i-1 >= len(b.snippet.Lines) {
 			continue
 		}
 
 		line := expandTabs(b.snippet.Lines[i-1])
+		line = strings.TrimPrefix(line, commonIndent)
 		lineNum := fmt.Sprintf("%*d", maxLineNumWidth, i)
 
 		b.result.WriteString(lineStyle.Sprintf("%s | ", lineNum))
@@ -156,14 +165,22 @@ func (b *IssueFormatterBuilder) AddUnderlineAndMessage() *IssueFormatterBuilder
 
 	b.result.WriteString(lineStyle.Sprintf("%s| ", padding))
 
-	if startLine <= 0 || startLine > len(b.snippet.Lines) || endLine <= 0 || endLine > len(b.snippet.Lines) {
+	if startLine <= 0 || startLine > len(b.snippet.Lines) || endLine <= 0 || endLine > len(b.snippet.Lines) || startLine > endLine {
 		b.result.WriteString(messageStyle.Sprintf("%s\n\n", b.issue.Message))
 		return b
 	}
 
-	// draw underline from start column to end column
-	underlineStart := calculateVisualColumn(b.snippet.Lines[startLine-1], b.issue.Start.Column)
-	underlineEnd := calculateVisualColumn(b.snippet.Lines[endLine-1], b.issue.End.Column)
+	commonIndent := findCommonIndent(b.snippet.Lines[startLine-1 : endLine])
+	commonIndentWidth := calculateVisualColumn(commonIndent, len(commonIndent)+1)
+
+	// calculate underline start position
+	underlineStart := calculateVisualColumn(b.snippet.Lines[startLine-1], b.issue.Start.Column) - commonIndentWidth
+	if underlineStart < 0 {
+		underlineStart = 0
+	}
+
+	// calculate underline end position
+	underlineEnd := calculateVisualColumn(b.snippet.Lines[endLine-1], b.issue.End.Column) - commonIndentWidth
 	underlineLength := underlineEnd - underlineStart + 1
 
 	b.result.WriteString(strings.Repeat(" ", underlineStart))
@@ -219,17 +236,6 @@ func (b *IssueFormatterBuilder) AddNote() *IssueFormatterBuilder {
 
 type BaseFormatter struct{}
 
-func (f *BaseFormatter) Format(issue tt.Issue, snippet *internal.SourceCode) string {
-	builder := NewIssueFormatterBuilder(issue, snippet)
-	return builder.
-		AddHeader(warningHeader).
-		AddCodeSnippet().
-		AddUnderlineAndMessage().
-		AddSuggestion().
-		AddNote().
-		Build()
-}
-
 func (b *IssueFormatterBuilder) Build() string {
 	return b.result.String()
 }
@@ -272,3 +278,27 @@ func calculateVisualColumn(line string, column int) int {
 	}
 	return visualColumn
 }
+
+func findCommonIndent(lines []string) string {
+	if len(lines) == 0 {
+		return ""
+	}
+
+	commonIndentPrefix := strings.TrimLeft(lines[0], " \t")
+	commonIndentPrefix = lines[0][:len(lines[0])-len(commonIndentPrefix)]
+
+	for _, line := range lines[1:] {
+		if strings.TrimSpace(line) == "" {
+			continue // ignore empty lines
+		}
+
+		for !strings.HasPrefix(line, commonIndentPrefix) {
+			commonIndentPrefix = commonIndentPrefix[:len(commonIndentPrefix)-1]
+			if len(commonIndentPrefix) == 0 {
+				return ""
+			}
+		}
+	}
+
+	return commonIndentPrefix
+}
diff --git a/formatter/formatter_test.go b/formatter/formatter_test.go
@@ -42,15 +42,15 @@ func TestFormatIssuesWithArrows(t *testing.T) {
 	expected := `error: unused-variable
  --> test.go
   |
-4 |     x := 1
-  |     ~~
+4 | x := 1
+  | ~~
   | x declared but not used
 
 error: empty-if
  --> test.go
   |
-5 |     if true {}
-  |     ~~~~~~~~~
+5 | if true {}
+  | ~~~~~~~~~
   | empty branch
 
 `
@@ -74,15 +74,15 @@ error: empty-if
 	expectedWithTabs := `error: unused-variable
  --> test.go
   |
-4 |     x := 1
-  |     ~~
+4 | x := 1
+  | ~~
   | x declared but not used
 
 error: empty-if
  --> test.go
   |
-5 |     if true {}
-  |     ~~~~~~~~~
+5 | if true {}
+  | ~~~~~~~~~
   | empty branch
 
 `
@@ -136,22 +136,22 @@ func TestFormatIssuesWithArrows_MultipleDigitsLineNumbers(t *testing.T) {
 	expected := `error: unused-variable
  --> test.go
   |
-4 |     x := 1  // unused variable
-  |     ~~
+4 | x := 1  // unused variable
+  | ~~
   | x declared but not used
 
 error: empty-if
  --> test.go
   |
-5 |     if true {}  // empty if statement
-  |     ~~~~~~~~~
+5 | if true {}  // empty if statement
+  | ~~~~~~~~~
   | empty branch
 
 error: example
   --> test.go
    |
-10 |     println("end")
-   |     ~~~~~~~~
+10 | println("end")
+   | ~~~~~~~~
    | example issue
 
 `
@@ -244,8 +244,8 @@ func TestUnnecessaryTypeConversionFormatter(t *testing.T) {
 	expected := `error: unnecessary-type-conversion
  --> test.go
   |
-5 |     result := int(myInt)
-  |          ~~~~~~~~~~~
+5 | result := int(myInt)
+  |      ~~~~~~~~~~~
   | unnecessary type conversion
 
 Suggestion:
@@ -261,3 +261,82 @@ Note: Unnecessary type conversions can make the code less readable and may sligh
 
 	assert.Equal(t, expected, result, "Formatted output should match expected output")
 }
+
+func TestFindCommonIndent(t *testing.T) {
+	tests := []struct {
+		name     string
+		lines    []string
+		expected string
+	}{
+		{
+			name: "whitespace indent",
+			lines: []string{
+				"    if foo {",
+				"        println()",
+				"    }",
+			},
+			expected: "    ",
+		},
+		{
+			name: "tab indent",
+			lines: []string{
+				"\tif foo {",
+				"\t\tprintln()",
+				"\t}",
+			},
+			expected: "\t",
+		},
+		{
+			name: "mixed indent (space and tab)",
+			lines: []string{
+				"\t    if foo {",
+				"\t    \tprintln()",
+				"\t    }",
+			},
+			expected: "\t    ",
+		},
+		{
+			name: "no indent",
+			lines: []string{
+				"if foo {",
+				"println()",
+				"}",
+			},
+			expected: "",
+		},
+		{
+			name: "empty line",
+			lines: []string{
+				"    if foo {",
+				"",
+				"        println()",
+				"    }",
+			},
+			expected: "    ",
+		},
+		{
+			name: "various indent levels",
+			lines: []string{
+				"    if foo {",
+				"      bar()",
+				"        baz()",
+				"    }",
+			},
+			expected: "    ",
+		},
+		{
+			name:     "empty input",
+			lines:    []string{},
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := findCommonIndent(tt.lines)
+			if result != tt.expected {
+				t.Errorf("findCommonIndent() = %q, want %q", result, tt.expected)
+			}
+		})
+	}
+}
diff --git a/internal/fixer/fixer_test.go b/internal/fixer/fixer_test.go
@@ -183,10 +183,10 @@ func main() {
 }`,
 			issues: []tt.Issue{
 				{
-					Rule:     "emit-format",
-					Message:  "Consider formatting std.Emit call for better readability",
-					Start:    token.Position{Line: 8, Column: 5},
-					End:      token.Position{Line: 9, Column: 44},
+					Rule:    "emit-format",
+					Message: "Consider formatting std.Emit call for better readability",
+					Start:   token.Position{Line: 8, Column: 5},
+					End:     token.Position{Line: 9, Column: 44},
 					Suggestion: `std.Emit(
     "OwnershipChange",
     "newOwner", newOwner,