Baselines, budgets and CI

Baseline comparison

With compareWithPrevious: true (the default) the integration reads the JSON report at outputFile before writing the new one, and logs the difference in total build time as astro-speed-measure: Previous build: <previous> -> <current> (▲<difference>), with ▼ when the build got faster.

The file is written for every output mode except a custom function. A .html outputFile is paired with a .json file of the same name for the baseline.

In CI the working directory starts empty, so there is no previous report unless you restore it, for example from a cache or an artifact of the last build on the default branch.

Budgets

speedMeasure({
  budgets: {
    totalBuild: 30000, // ms
    integration: 2000,
    plugin: 1500,
    page: 1000,
  },
});

Each exceeded budget logs a warning in the form astro-speed-measure: Vite plugin "<name>" took <time> (budget <budget>), and likewise for the total build time, integrations and pages.

integration, plugin and page apply to every single integration, plugin and page. Budgets warn only; the build does not fail.

GitHub Actions step summary

When GITHUB_STEP_SUMMARY is set, the integration appends a short Markdown summary to it: the total build time and the slowest integration, Vite plugin and page. It shows up on the run’s summary page. Set ciSummary: false to skip it.

JSON for your own pipeline

speedMeasure({
  output: 'json',
  outputFile: './build-metrics.json',
});

The file contains the full report. Upload it as an artifact, or pass a function as output to send the report wherever you need it.