setup-dotnet/src/setup-dotnet.ts

import * as core from '@actions/core';
import * as installer from './installer';
import * as fs from 'fs';
import * as path from 'path';
import * as auth from './authutil';

export async function run() {
  try {
    //
    // dotnet-version is optional, but needs to be provided for most use cases.
    // If supplied, install / use from the tool cache.
    // global-version-file may be specified to point to a specific global.json
    // and will be used to install an additional version.
    // If not supplied, look for version in ./global.json.
    // If a valid version still can't be identified, nothing will be installed.
    // Proxy, auth, (etc) are still set up, even if no version is identified
    //
    let versions = core.getMultilineInput('dotnet-version');

    const globalJsonFileInput = core.getInput('global-json-file');
    if (globalJsonFileInput) {
      const globalJsonPath = path.join(process.cwd(), globalJsonFileInput);
      if (!fs.existsSync(globalJsonPath)) {
        throw new Error(
          `The specified global.json file '${globalJsonFileInput}' does not exist`
        );
      }
      versions.push(getVersionFromGlobalJson(globalJsonPath));
    }

    if (!versions.length) {
      // Try to fall back to global.json
      core.debug('No version found, trying to find version from global.json');
      const globalJsonPath = path.join(process.cwd(), 'global.json');
      if (fs.existsSync(globalJsonPath)) {
        versions.push(getVersionFromGlobalJson(globalJsonPath));
      }
    }

    if (versions.length) {
      const includePrerelease: boolean = core.getBooleanInput(
        'include-prerelease'
      );
      let dotnetInstaller!: installer.DotnetCoreInstaller;
      for (const version of new Set<string>(versions)) {
        dotnetInstaller = new installer.DotnetCoreInstaller(
          version,
          includePrerelease
        );
        await dotnetInstaller.installDotnet();
      }
      installer.DotnetCoreInstaller.addToPath();
    }

    const sourceUrl: string = core.getInput('source-url');
    const configFile: string = core.getInput('config-file');
    if (sourceUrl) {
      auth.configAuthentication(sourceUrl, configFile);
    }

    const matchersPath = path.join(__dirname, '..', '.github');
    console.log(`##[add-matcher]${path.join(matchersPath, 'csc.json')}`);
  } catch (error) {
    core.setFailed(error.message);
  }
}

function getVersionFromGlobalJson(globalJsonPath: string): string {
  let version: string = '';
  const globalJson = JSON.parse(
    // .trim() is necessary to strip BOM https://github.com/nodejs/node/issues/20649
    fs.readFileSync(globalJsonPath, {encoding: 'utf8'}).trim()
  );
  if (globalJson.sdk && globalJson.sdk.version) {
    version = globalJson.sdk.version;
    const rollForward = globalJson.sdk.rollForward;
    if (rollForward && rollForward === 'latestFeature') {
      const [major, minor] = version.split('.');
      version = `${major}.${minor}`;
    }
  }
  return version;
}

run();