Preview Report

Batch Preview Report

Capture screenshots of all #Preview blocks across multiple SwiftUI files and generate a report.

Steps

1. Determine target files

If $ARGUMENTS specifies files, use those directly. $ARGUMENTS may contain only View names (e.g. ContentView) instead of file paths, so resolve each to a .swift path (e.g. TodoApp/ContentView.swift) using Glob.

If no arguments are provided, detect changed Swift files:

FILES=$(git diff --name-only --diff-filter=ACMR HEAD -- '*.swift')
if [ -z "$FILES" ]; then
  echo "No changed Swift files found. Specify files explicitly."
  exit 1
fi

2. Generate the report

axe preview report $FILES --format md --output <output-dir>

When $ARGUMENTS is provided, use $ARGUMENTS instead of $FILES:

axe preview report $ARGUMENTS --format md --output <output-dir>

This generates:

• axe_swiftui_preview_report.md — Markdown report with embedded image references
• axe_swiftui_preview_report_assets/*.png — Individual preview screenshots

3. Display the results

Read the generated Markdown report with the Read tool. Then read each preview image in the assets directory to show them to the user.

4. Summarize

Provide a summary of all captured previews, noting:

• Total number of #Preview blocks found
• Any previews that failed to capture (and likely reasons from stderr)
• Quick observations about the UI state of each view

Options

• Use -j <n> to control parallel simulator count for faster capture
• Use --reuse-build to skip rebuilding if the project was recently built
• Replace --format md with --format html for an interactive HTML report with lightbox

Use Cases

• PR review: Capture all changed views before creating a pull request
• Visual regression: Compare previews across branches
• Documentation: Generate a visual catalog of UI components

Prerequisites

Run this if the command fails because axe is not found::

curl -fsSL https://raw.githubusercontent.com/k-kohey/axe/main/install.sh | sh

Source: k-kohey/axe — distributed by TomeVault.