v2 iteration on testing codeblocks

This commit is v2 approach to testing for accessible colors and codeblock rendering using an in-house approach to identifying ANSI escape sequences and analyzing them for color depth.

After talking with @williammartin, this is likely going to be refactored a third time leveraging a module to help with parsing escape sequences from text.

go.mod

@@ -5,9 +5,9 @@ go 1.21
 require (
 	github.com/AlecAivazis/survey/v2 v2.3.7
 	github.com/MakeNowJust/heredoc v1.0.0
-	github.com/charmbracelet/glamour v0.8.0
 	github.com/charmbracelet/lipgloss v1.0.0
 	github.com/cli/browser v1.3.0
+	github.com/cli/glamour v0.0.0-20250220192152-8544502ccff9
 	github.com/cli/safeexec v1.0.0
 	github.com/cli/shurcooL-graphql v0.0.4
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
@@ -49,5 +49,3 @@ require (
 	golang.org/x/net v0.33.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 )
-
-replace github.com/charmbracelet/glamour => github.com/cli/glamour v0.0.0-20250219132354-dba8cf7ee336

go.sum

@@ -24,8 +24,8 @@ github.com/charmbracelet/x/exp/golden v0.0.0-20240806155701-69247e0abc2a h1:G99k
 github.com/charmbracelet/x/exp/golden v0.0.0-20240806155701-69247e0abc2a/go.mod h1:wDlXFlCrmJ8J+swcL/MnGUuYnqgQdW9rhSD61oNMb6U=
 github.com/cli/browser v1.3.0 h1:LejqCrpWr+1pRqmEPDGnTZOjsMe7sehifLynZJuqJpo=
 github.com/cli/browser v1.3.0/go.mod h1:HH8s+fOAxjhQoBUAsKuPCbqUuxZDhQ2/aD+SzsEfBTk=
-github.com/cli/glamour v0.0.0-20250219132354-dba8cf7ee336 h1:8C3iXVZ6ZP8MblfrT1KKPMgW0q1ZO9nXSPvpKy79VEk=
-github.com/cli/glamour v0.0.0-20250219132354-dba8cf7ee336/go.mod h1:OUgq8/2KmRHaylj8o+SGSoOiY+D0bNJfwaqN15oK4A0=
+github.com/cli/glamour v0.0.0-20250220192152-8544502ccff9 h1:fPJNUzG+Au+pIfYx2c5QNngZ3KLj7xAzjutL6efy1x8=
+github.com/cli/glamour v0.0.0-20250220192152-8544502ccff9/go.mod h1:bB4uNJ5F0+nzpGqwlhKEy7tD0PPL0SxNWEwZzG77vMg=
 github.com/cli/safeexec v1.0.0 h1:0VngyaIyqACHdcMNWfo6+KdUYnqEr2Sg+bSP1pdF+dI=
 github.com/cli/safeexec v1.0.0/go.mod h1:Z/D4tTN8Vs5gXYHDCbaM1S/anmEDnJb1iW0+EJ5zx3Q=
 github.com/cli/shurcooL-graphql v0.0.4 h1:6MogPnQJLjKkaXPyGqPRXOI2qCsQdqNfUY1QSJu2GuY=

pkg/markdown/accessibility.go

@@ -3,8 +3,8 @@ package markdown
 import (
 	"strconv"
 
-	"github.com/charmbracelet/glamour/ansi"
-	"github.com/charmbracelet/glamour/styles"
+	"github.com/cli/glamour/ansi"
+	"github.com/cli/glamour/styles"
 )
 
 type ANSIColorCode int

pkg/markdown/accessibility_test.go

@@ -3,8 +3,8 @@ package markdown
 import (
 	"testing"
 
-	"github.com/charmbracelet/glamour/ansi"
-	"github.com/charmbracelet/glamour/styles"
+	"github.com/cli/glamour/ansi"
+	"github.com/cli/glamour/styles"
 	"github.com/stretchr/testify/assert"
 )
 

pkg/markdown/markdown.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/charmbracelet/glamour"
+	"github.com/cli/glamour"
 	"github.com/cli/go-gh/v2/pkg/accessibility"
 )
 

pkg/markdown/markdown_test.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -20,8 +22,140 @@ const (
 	customH2_8bitColorSeq       = "\x1b[38;5;61;"
 	magenta_4bitColorSeq        = "\x1b[35;"
 	brightMagenta_4bitColorSeq  = "\x1b[95;"
+
+	// TODO: Include a little more context on SGR including link to https://en.wikipedia.org/wiki/ANSI_escape_code#Select_Graphic_Rendition_parameters for more info
+	// sgrSequencePattern identifies ANSI escape sequences containing display attributes
+	// that affect the color, emphasis, and other aspects of displaying text.
+	sgrSequencePattern = `\x1b\[(.+?)m`
+
+	// sgrAttributePattern analyzes separate display attributes within an ANSI escape sequence
+	// for detecting color depth (3-bit, 4-bit, 8-bit, 24-bit, etc) or other effects.
+	//
+	// This is a separate regex from sgrSequencePattern as `FindAllStringSubmatch()` does not
+	// handle repeating capture groups well.
+	sgrAttributePattern = `;?(?P<sequence>\d+)` // TODO: change the `sequence` note; if we aren't actually using the name group, remove it
 )
 
+func Test_Render_Codeblocks(t *testing.T) {
+	t.Setenv("GLAMOUR_STYLE", "")
+
+	sequencesRegex := regexp.MustCompile(sgrSequencePattern)
+	attributesRegex := regexp.MustCompile(sgrAttributePattern)
+	text := heredoc.Docf(`
+		%[1]s%[1]s%[1]sgo
+		package main
+
+		import (
+			"fmt"
+		)
+
+		func main() {
+			fmt.Println("Hello, world!")
+		}
+		%[1]s%[1]s%[1]s
+	`, "`")
+
+	tests := []struct {
+		name       string
+		text       string
+		theme      string
+		accessible bool
+	}{
+		{
+			name:  "when the light theme is selected, the codeblock renders using 8-bit colors",
+			text:  text,
+			theme: "light",
+		},
+		{
+			name:  "when the dark theme is selected, the codeblock renders using 8-bit colors",
+			text:  text,
+			theme: "dark",
+		},
+		{
+			name:       "when the accessible env var is set and the light theme is selected, the codeblock renders using 4-bit colors",
+			text:       text,
+			theme:      "light",
+			accessible: true,
+		},
+		{
+			name:       "when the accessible env var is set and the dark theme is selected, the codeblock renders using 4-bit colors",
+			text:       text,
+			theme:      "dark",
+			accessible: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.accessible {
+				t.Setenv(accessibility.ACCESSIBILITY_ENV, "true")
+			}
+
+			out, err := Render(tt.text, WithTheme(tt.theme))
+			require.NoError(t, err)
+			sequences := sequencesRegex.FindAllStringSubmatch(out, -1)
+			require.NotEmpty(t, sequences, "Failed to find expected SGR sequences in rendered output")
+
+			// TODO: Review use of a module like https://github.com/leaanthony/go-ansi-parser/blob/main/ansi.go#L264 to do the sequence and attribute parsing such that we just have to iterate over the results
+			for _, sequence := range sequences {
+				attributes := attributesRegex.FindAllStringSubmatch(sequence[1], -1)
+				require.NotEmpty(t, attributes, "Failed to extract SGR attributes for testing")
+
+				// Analysis loop handles index incrementing due to unique display attribute situations like color depth
+				for i := 0; i < len(attributes); {
+					// TODO: Use constants for 38,48 and maybe remove the int conversion
+					attribute, err := strconv.Atoi(attributes[i][1])
+					require.NoError(t, err, "Failed to convert SGR attribute for testing")
+
+					switch attribute {
+					case 38, 48:
+						// Display attributes for setting 8-bit and 24-bit foreground and background colors
+						colorDepth, err := strconv.Atoi(attributes[i+1][1])
+						require.NoError(t, err, "Failed to convert SGR color depth attribute for testing")
+
+						switch colorDepth {
+						case 2:
+							// 24-bit color display attribute form
+							// - ESC[38;2;⟨r⟩;⟨g⟩;⟨b⟩m for foreground colors
+							// - ESC[48;2;⟨r⟩;⟨g⟩;⟨b⟩m for background colors
+							require.False(t, tt.accessible, "24-bit color is not accessible, customizable")
+
+							color24bitRed, err := strconv.Atoi(attributes[i+2][1])
+							require.NoError(t, err, "Failed to convert 24-bit red color value for testing")
+							require.True(t, color24bitRed >= 0 && color24bitRed <= 255, "24-bit red color value out of 0-255 range")
+
+							color24bitGreen, err := strconv.Atoi(attributes[i+3][1])
+							require.NoError(t, err, "Failed to convert 24-bit green color value for testing")
+							require.True(t, color24bitGreen >= 0 && color24bitGreen <= 255, "24-bit green color value out of 0-255 range")
+
+							color24bitBlue, err := strconv.Atoi(attributes[i+4][1])
+							require.NoError(t, err, "Failed to convert 24-bit blue color value for testing")
+							require.True(t, color24bitBlue >= 0 && color24bitBlue <= 255, "24-bit blue color value out of 0-255 range")
+
+							i += 5
+						case 5:
+							// 8-bit color display attributes form:
+							// - ESC[38;5;⟨n⟩m for foreground colors
+							// - ESC[48;5;⟨n⟩m for background colors
+							require.False(t, tt.accessible, "8-bit color is not accessible, customizable")
+
+							color8bit, err := strconv.Atoi(attributes[i+2][1])
+							require.NoError(t, err, "Failed to convert 8-bit color value for testing")
+							require.True(t, color8bit >= 0 && color8bit <= 255, "8-bit color value out of 0-255 range")
+
+							i += 3
+						default:
+							require.Fail(t, "Unexpected color depth in attribute")
+						}
+					default:
+						// Increment index as this attribute does not affect accessibility currently
+						i += 1
+					}
+				}
+			}
+		})
+	}
+}
+
 // Test_Render verifies that the proper ANSI color codes are applied to the rendered
 // markdown by examining the ANSI escape sequences in the output for the correct color
 // match. For more information on ANSI color codes, see
@@ -75,48 +209,6 @@ func Test_Render(t *testing.T) {
 			accessibleEnvVar: "true",
 			wantOut:          fmt.Sprintf("%s1mh2", brightMagenta_4bitColorSeq),
 		},
-		{
-			name: "when the light theme is selected, the codeblock renders using 8-bit colors",
-			text: heredoc.Docf(`
-				%[1]s%[1]s%[1]sgo
-				fmt.Println("Hello, world!")
-				%[1]s%[1]s%[1]s
-			`, "`"),
-			theme:   "light",
-			wantOut: "\x1b[0m\x1b[38;5;235mfmt\x1b[0m\x1b[38;5;210m.\x1b[0m\x1b[38;5;35mPrintln\x1b[0m\x1b[38;5;210m(\x1b[0m\x1b[38;5;95m\"Hello, world!\"\x1b[0m\x1b[38;5;210m)\x1b[0m",
-		},
-		{
-			name: "when the dark theme is selected, the codeblock renders using 8-bit colors",
-			text: heredoc.Docf(`
-				%[1]s%[1]s%[1]sgo
-				fmt.Println("Hello, world!")
-				%[1]s%[1]s%[1]s
-			`, "`"),
-			theme:   "dark",
-			wantOut: "\x1b[0m\x1b[38;5;235mfmt\x1b[0m\x1b[38;5;210m.\x1b[0m\x1b[38;5;35mPrintln\x1b[0m\x1b[38;5;210m(\x1b[0m\x1b[38;5;95m\"Hello, world!\"\x1b[0m\x1b[38;5;210m)\x1b[0m",
-		},
-		{
-			name: "when the accessible env var is set and the light theme is selected, the codeblock renders using 4-bit colors",
-			text: heredoc.Docf(`
-				%[1]s%[1]s%[1]sgo
-				fmt.Println("Hello, world!")
-				%[1]s%[1]s%[1]s
-			`, "`"),
-			theme:            "light",
-			accessibleEnvVar: "true",
-			wantOut:          "\x1b[0m\x1b[30mfmt\x1b[0m\x1b[33m.\x1b[0m\x1b[36mPrintln\x1b[0m\x1b[33m(\x1b[0m\x1b[90m\"Hello, world!\"\x1b[0m\x1b[33m)\x1b[0m",
-		},
-		{
-			name: "when the accessible env var is set and the dark theme is selected, the codeblock renders using 4-bit colors",
-			text: heredoc.Docf(`
-				%[1]s%[1]s%[1]sgo
-				fmt.Println("Hello, world!")
-				%[1]s%[1]s%[1]s
-			`, "`"),
-			theme:            "dark",
-			accessibleEnvVar: "true",
-			wantOut:          "\x1b[0m\x1b[30mfmt\x1b[0m\x1b[33m.\x1b[0m\x1b[36mPrintln\x1b[0m\x1b[33m(\x1b[0m\x1b[90m\"Hello, world!\"\x1b[0m\x1b[33m)\x1b[0m",
-		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {