Add test case and fix colorization bug for inline arrays in TOML

Co-authored-by: mikefarah <1151925+mikefarah@users.noreply.github.com>

pkg/yqlib/encoder_toml.go

@@ -565,27 +565,50 @@ func (te *tomlEncoder) colorizeToml(input []byte) []byte {
 		}
 
 		// Table sections - [section] or [[array]]
+		// Only treat '[' as a table section if it appears at the start of the line
+		// (possibly after whitespace). This avoids mis-coloring inline arrays like
+		// "ports = [8000, 8001]" as table sections.
 		if ch == '[' {
-			end := i + 1
-			// Check for [[
-			if end < len(toml) && toml[end] == '[' {
-				end++
-			}
-			// Find closing ]
-			for end < len(toml) && toml[end] != ']' {
-				end++
-			}
-			// Include closing ]
-			if end < len(toml) {
-				end++
-				// Check for ]]
-				if end < len(toml) && toml[end] == ']' {
-					end++
+			isSectionHeader := true
+			if i > 0 {
+				isSectionHeader = false
+				j := i - 1
+				for j >= 0 && toml[j] != '\n' {
+					if toml[j] != ' ' && toml[j] != '\t' && toml[j] != '\r' {
+						// Found a non-whitespace character before this '[' on the same line,
+						// so this is not a table header.
+						break
+					}
+					j--
+				}
+				if j < 0 || toml[j] == '\n' {
+					// Reached the start of the string or a newline without encountering
+					// any non-whitespace, so '[' is at the logical start of the line.
+					isSectionHeader = true
 				}
 			}
-			result.WriteString(sectionColor(toml[i:end]))
-			i = end
-			continue
+			if isSectionHeader {
+				end := i + 1
+				// Check for [[
+				if end < len(toml) && toml[end] == '[' {
+					end++
+				}
+				// Find closing ]
+				for end < len(toml) && toml[end] != ']' {
+					end++
+				}
+				// Include closing ]
+				if end < len(toml) {
+					end++
+					// Check for ]]
+					if end < len(toml) && toml[end] == ']' {
+						end++
+					}
+				}
+				result.WriteString(sectionColor(toml[i:end]))
+				i = end
+				continue
+			}
 		}
 
 		// Strings - quoted text (double or single quotes)

pkg/yqlib/toml_test.go

@@ -3,8 +3,10 @@ package yqlib
 import (
 	"bufio"
 	"fmt"
+	"strings"
 	"testing"
 
+	"github.com/fatih/color"
 	"github.com/mikefarah/yq/v4/test"
 )
 
@@ -625,3 +627,61 @@ func TestTomlScenarios(t *testing.T) {
 	}
 	documentScenarios(t, "usage", "toml", genericScenarios, documentTomlScenario)
 }
+
+// TestTomlColorization tests that colorization correctly distinguishes
+// between table section headers and inline arrays
+func TestTomlColorization(t *testing.T) {
+	// Test that inline arrays are not colored as table sections
+	encoder := &tomlEncoder{prefs: TomlPreferences{ColorsEnabled: true}}
+	
+	// Create TOML with both table sections and inline arrays
+	input := []byte(`[database]
+enabled = true
+ports = [8000, 8001, 8002]
+
+[servers]
+alpha = "test"
+`)
+	
+	result := encoder.colorizeToml(input)
+	resultStr := string(result)
+	
+	// The bug would cause the inline array [8000, 8001, 8002] to be
+	// colored with the section color (Yellow + Bold) instead of being
+	// left uncolored or colored differently.
+	// 
+	// To test this, we check that the section color codes appear only
+	// for actual table sections, not for inline arrays.
+	
+	// Get the ANSI codes for section color (Yellow + Bold)
+	sectionColor := color.New(color.FgYellow, color.Bold).SprintFunc()
+	sampleSection := sectionColor("[database]")
+	
+	// Extract just the ANSI codes from the sample
+	// ANSI codes start with \x1b[
+	var ansiStart string
+	for i := 0; i < len(sampleSection); i++ {
+		if sampleSection[i] == '\x1b' {
+			// Find the end of the ANSI sequence (ends with 'm')
+			end := i
+			for end < len(sampleSection) && sampleSection[end] != 'm' {
+				end++
+			}
+			if end < len(sampleSection) {
+				ansiStart = sampleSection[i : end+1]
+				break
+			}
+		}
+	}
+	
+	// Count how many times the section color appears in the output
+	// It should appear exactly twice: once for [database] and once for [servers]
+	// If it appears more times (e.g., for [8000, 8001, 8002]), that's the bug
+	sectionColorCount := strings.Count(resultStr, ansiStart)
+	
+	// We expect exactly 2 occurrences (for [database] and [servers])
+	// The bug would cause more occurrences (e.g., also for [8000)
+	if sectionColorCount != 2 {
+		t.Errorf("Expected section color to appear exactly 2 times (for [database] and [servers]), but it appeared %d times.\nOutput: %s", sectionColorCount, resultStr)
+	}
+}