Add integration test for commit highlighting on focus

A better refactor would be to allow matchers to assert against either a string or a slice of cells, so that I could have
the same ergonomics that I have elsewhere, but this is a start.

vendor/github.com/jesseduffield/gocui/view.go

@@ -13,6 +13,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
+	"github.com/gdamore/tcell/v2"
 	"github.com/go-errors/errors"
 	"github.com/mattn/go-runewidth"
 )
@@ -1461,3 +1462,38 @@ func (v *View) scrollMargin() int {
 		return 0
 	}
 }
+
+// Returns true if the view contains a line containing the given text with the given
+// foreground color
+func (v *View) ContainsColoredText(fgColor string, text string) bool {
+	for _, line := range v.lines {
+		if containsColoredTextInLine(fgColor, text, line) {
+			return true
+		}
+	}
+
+	return false
+}
+
+func containsColoredTextInLine(fgColorStr string, text string, line []cell) bool {
+	fgColor := tcell.GetColor(fgColorStr)
+
+	currentMatch := ""
+	for i := 0; i < len(line); i++ {
+		cell := line[i]
+
+		// stripping attributes by converting to and from hex
+		cellColor := tcell.NewHexColor(cell.fgColor.Hex())
+
+		if cellColor == fgColor {
+			currentMatch += string(cell.chr)
+		} else if currentMatch != "" {
+			if strings.Contains(currentMatch, text) {
+				return true
+			}
+			currentMatch = ""
+		}
+	}
+
+	return strings.Contains(currentMatch, text)
+}