Running a codometer measurement

Codometer walks a directory, parses everything it recognizes, and reports what it counted — as console output, a JSON report, a markdown document, or a badge block spliced into an existing file. It counts languages the way any analyzer would — files, lines, classes, functions — and also the declared conventions a repository holds itself to, which is usually the more interesting number.

One directory at a time

Codometer measures one directory and knows nothing about workspaces, task runners, or project graphs. Pointed at a project, it measures that project's own sources and whatever inputs its configuration declares — nothing else, and nothing about sibling projects. There is no --directory: a run always measures the process's working directory, with no per-invocation override.

cd packages/widgets && codometer --check limits

Do not assume it takes a project name, a package name, or anything a task runner would resolve. If a workspace runs it per project, that iteration is the runner's job, not codometer's. --inputs [globs...] narrows a single run to exactly the globs given, running only language analysis over them, with no configured input — not even the built-in codebase one — active.

Finding the configuration

With no --config, codometer searches upward from the measured directory and takes the first configuration file it finds. The nearest one wins outright: nothing from a further ancestor is folded into it. A project with no configuration of its own is measured by the nearest ancestor's, in full. A configuration file is always read as a plain object — exporting a function is not recognized and falls back to an empty configuration.

.gitignore is already in force through discovery — a build directory or virtual environment pruned by an ignore file needs no exclusion naming it again — and git itself is never invoked, so an unversioned directory measures the same way a repository does.

Every flag is independent

--output-json, --output-markdown, --check, and --format are asked for separately, and none of them turns another on:

--output-json/--output-markdown passed bare write wherever the resolved configuration's own output of that kind declares, and are refused before anything is measured when the configuration names no such output — there is then nowhere to write it. Passed with a path, that path is used for this run alone, whether or not the configuration declares an output of that kind: codometer --output-json report.json writes there regardless of what outputs says.

Combining an --output-* flag with --check reports is refused rather than obeyed: nothing can be stale in the run that just wrote it. A run that both writes and gates still produces every resolved output before it fails, so the report on disk reflects the current measurement even when the run's exit code says no.

A breach and staleness are different findings, never reported as one. A warn-severity breach prints and leaves the exit code alone; a fail-severity breach exits 1, and only where --check limits asked for a gate at all. For what to do about either, reach for the codometer-triage skill.

- run: npx @codometer/cli --check limits,reports

Reading a report

The JSON report groups metrics by target. Every metric carries its value, its path within its target, a unit ("bytes" or null), every limit declared against it, and — for a comment selector's metric — the instances where each breaching block was found:

{
  "failures": [],
  "targets": [
    {
      "empty": false,
      "files": 42,
      "name": "codebase",
      "metrics": [
        {
          "instances": null,
          "limits": [{ "breached": false, "label": null, "severity": "fail", "value": 500 }],
          "name": "codebase.typescript.interfaces",
          "path": "typescript.interfaces",
          "unit": null,
          "value": 118
        },
        {
          "instances": [{ "file": "src/main.ts", "line": 4, "measured": 214 }],
          "limits": [{ "breached": true, "label": null, "severity": "fail", "value": 0 }],
          "name": "codebase.custom.TypeScript Comment Budget",
          "path": "custom.TypeScript Comment Budget",
          "unit": null,
          "value": 1
        }
      ]
    }
  ]
}

A limit that held is written out exactly like one that did not, so a consumer can render headroom, not only failures. A comment selector's value counts the blocks that broke its own budget, and instances names each one's file and line — null on any metric that only counts. failures holds what the run could not do at all — a target that matched no files despite carrying a limit, a limit bound to a metric nothing measured — and is unrelated to a breach or staleness.

Where output goes

What a run prints and what it writes are asked for separately. --format json prints the report and --format markdown prints the rendered badges; a path always names a file, never the console. Left off, --format falls back to the resolved configuration's own required format field — never inferred from which other flags are present.

Two file sinks — --output-json [path] and --output-markdown [path] — neither of which implies the other or implies printing.

--output-markdown writes into a file somebody else may have written the rest of. The block sits between two markers, named <!-- codometer:start --> / <!-- codometer:end --> unless the configuration renames them; it is spliced between them when they are there, appended with them when they are not, and the file is created when it does not exist.

Every file codometer would write is excluded from what it measures, on every run regardless of flags — a written report left in the count would be stale the instant it landed, and a splice would move the very markdown metrics it just wrote into.

A runtime detail that reads like a bug

Compressed sizes are Node-version dependent, because the bundled zlib differs between releases. A report written on one Node runtime and checked on another reads as stale even when nothing in the source changed. Run --check reports on the same runtime the repository pins for everything else, and reach for the codometer-triage skill before concluding a stale report is a real regression.