Add visual regression tests with golden files for console rendering

[Copilot]

Implements visual regression testing using github.com/charmbracelet/x/exp/golden to prevent unintended formatting changes in console output components (tables, boxes, trees, error messages).

Changes

• Golden test suite (pkg/console/golden_test.go)

  • 44 golden files covering 10 rendering categories
  • Table rendering: simple, titled, totaled, wide, empty variants
  • Box rendering: narrow/medium/wide widths, emoji content
  • Tree rendering: flat, nested, deep hierarchies (up to 5 levels)
  • Error formatting: basic, with hints, with source context
  • Message formatting: success, info, warning, error, location, command, progress
  • Layout composition: multi-element combinations

• Makefile target: make update-golden regenerates golden files after intentional formatting changes

• Documentation (specs/visual-regression-testing.md)

  • Usage patterns and golden file organization
  • TTY vs non-TTY output handling
  • Failure diagnosis with diff examples

Example

func TestGolden_TableRendering(t *testing.T) {
    config := TableConfig{
        Headers: []string{"Name", "Status", "Duration"},
        Rows: [][]string{
            {"test-1", "success", "1.2s"},
            {"test-2", "failed", "0.5s"},
        },
    }
    output := RenderTable(config)
    golden.RequireEqual(t, []byte(output))
}

Golden files capture plain-text output (non-TTY) for consistency across environments. Tests fail with unified diff when rendering changes unexpectedly.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• 4d63.com
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• cloud.google.com
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• codeberg.org
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• dev.gaijin.team
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• gitlab.com
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go-simpler.org
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go.augendre.info
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go.googlesource.com
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go.opentelemetry.io
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go.uber.org
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• go.yaml.in
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• google.golang.org
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• gopkg.in
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• honnef.co
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)
• https://api.github.com/user
  • Triggering command: /usr/bin/gh gh api user --jq .login -json GO111MODULE ux-amd64/bin/go GOINSECURE GOMOD GOMODCACHE go env -json GO111MODULE rg/toolchain@v0.-s GOINSECURE GOMOD GOMODCACHE go (http block)
• mvdan.cc
  • Triggering command: `/update-job-proxy /update-job-proxy l/linux_amd64/cocommit /usr/bin/infocmp-m /usr/lib/git-corComplete visual regression testing implementation

Co-authored-by: mnkiefer <8320933+mnkiefer@users.noreply.github.com> http�� ithub-script/git/ref/tags/v8 infocmp 6/x64/bin/node t/gh-aw/git/ref/git go` (dns block)

• Triggering command: /update-job-proxy /update-job-proxy DROP e1fb8a9a git -c 1cc9d80b66b8db84--stdin fetch /home/dependabot--alternate-refs --depth=1 %H %ct %D 4ea7f6d9 git -c tformat fetch /bin/git 7af297/shallow.l/usr/sbin/ip6tables origin 0 /usr/bin/git (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[plan] Add visual regression tests with golden files</issue_title>
<issue_description>## Objective

Implement visual regression testing for console output components using github.com/charmbracelet/x/exp/golden to prevent formatting regressions.

Context

The Terminal Stylist analysis (#8747) recommended adding visual regression tests to validate that console output rendering remains consistent across code changes, particularly for tables, boxes, and tree structures.

Approach

1. Add github.com/charmbracelet/x/exp/golden dependency
2. Create test directory structure for golden files (e.g., pkg/console/testdata/)
3. Write tests for key console components:
   • Table rendering with different terminal widths
   • Box rendering with various content lengths
   • Tree rendering with deep hierarchies
   • Error formatting with context
4. Generate initial golden files with current output
5. Add test helper functions for common golden test patterns
6. Document how to update golden files when output intentionally changes

Files to Create/Modify

• Create: pkg/console/golden_test.go - Golden file tests
• Create: pkg/console/testdata/ - Directory for golden files
• Update: go.mod - Add golden testing dependency
• Update: Makefile - Add target to update golden files
• Create: specs/visual-regression-testing.md - Documentation

Acceptance Criteria

• Golden tests exist for table rendering
• Golden tests exist for box rendering
• Golden tests exist for tree rendering
• Golden tests exist for error formatting
• Tests fail when output format changes unexpectedly
• Documentation explains how to update golden files
• Makefile target exists to regenerate golden files
• Tests cover different terminal widths
• Tests validate both TTY and non-TTY output

Example Test

func TestTableRenderingGolden(t *testing.T) {
    config := console.TableConfig{
        Headers: []string{"Name", "Status", "Duration"},
        Rows: [][]string{
            {"test-1", "success", "1.2s"},
            {"test-2", "failed", "0.5s"},
        },
    }
    output := console.RenderTable(config)
    golden.RequireEqual(t, []byte(output))
}

Related to #8748

AI generated by Plan Command for discussion #8747

Comments on the Issue (you are @copilot in this section)

• Fixes [plan] Add visual regression tests with golden files #8751

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.