coverage-node/coverage-node.mjs

#!/usr/bin/env node
// @ts-check

import { spawn } from "child_process";
import disposableDirectory from "disposable-directory";
import { yellow } from "kleur/colors";

import analyseCoverage from "./analyseCoverage.mjs";
import childProcessPromise from "./childProcessPromise.mjs";
import CliError from "./CliError.mjs";
import coverageSupported from "./coverageSupported.mjs";
import minNodeVersion from "./coverageSupportedMinNodeVersion.mjs";
import reportCliError from "./reportCliError.mjs";
import reportCoverage from "./reportCoverage.mjs";

/**
 * Powers the `coverage-node` CLI. Runs Node.js with the given arguments and
 * coverage enabled. An analysis of the coverage is reported to the console, and
 * if coverage is incomplete and there isn’t a truthy `ALLOW_MISSING_COVERAGE`
 * environment variable the process exits with code `1`.
 * @returns {Promise<void>} Resolves when all work is complete.
 */
async function coverageNode() {
  try {
    const [, , ...nodeArgs] = process.argv;

    if (!nodeArgs.length)
      throw new CliError("Node.js CLI arguments are required.");

    // eslint-disable-next-line curly
    if (coverageSupported) {
      await disposableDirectory(async (tempDirPath) => {
        const { exitCode } = await childProcessPromise(
          spawn("node", nodeArgs, {
            stdio: "inherit",
            env: { ...process.env, NODE_V8_COVERAGE: tempDirPath },
          })
        );

        // Only show a code coverage report if the Node.js script didn’t error,
        // to reduce distraction from the priority to solve errors.
        if (exitCode === 0) {
          const analysis = await analyseCoverage(tempDirPath);
          reportCoverage(analysis);
          if (analysis.uncovered.length && !process.env.ALLOW_MISSING_COVERAGE)
            process.exitCode = 1;
        } else if (exitCode !== null) process.exitCode = exitCode;
      });
      // coverage ignore next line
    } else {
      const { exitCode } = await childProcessPromise(
        spawn("node", nodeArgs, { stdio: "inherit" })
      );

      if (exitCode === 0)
        console.info(
          `\n${yellow(
            `Skipped code coverage as Node.js is ${process.version}, v${minNodeVersion.major}.${minNodeVersion.minor}.${minNodeVersion.patch}+ is supported.`
          )}\n`
        );
      else if (exitCode !== null) process.exitCode = exitCode;
    }
  } catch (error) {
    reportCliError(
      `Node.js${
        // coverage ignore next line
        coverageSupported ? " with coverage" : ""
      }`,
      error
    );

    process.exitCode = 1;
  }
}

coverageNode();