target.build = function()

in make.js [148:312]
113 lines of code
26 McCabe index (conditional complexity)

target.build = function() {
    target.clean();

    ensureTool('tsc', '--version', 'Version 2.3.4');
    ensureTool('npm', '--version', function (output) {
        if (semver.lt(output, '5.6.0')) {
            fail('Expected 5.6.0 or higher. To fix, run: npm install -g npm');
        }
    });

    taskList.forEach(function(taskName) {
        banner('Building: ' + taskName);
        var taskPath = path.join(__dirname, 'Tasks', taskName);
        ensureExists(taskPath);

        // load the task.json
        var outDir;
        var shouldBuildNode = test('-f', path.join(taskPath, 'tsconfig.json'));
        var taskJsonPath = path.join(taskPath, 'task.json');
        if (test('-f', taskJsonPath)) {
            var taskDef = fileToJson(taskJsonPath);
            validateTask(taskDef);

            // fixup the outDir (required for relative pathing in legacy L0 tests)
            outDir = path.join(buildPath, taskName);

            // create loc files
            createTaskLocJson(taskPath);
            createResjson(taskDef, taskPath);

            // determine the type of task
            shouldBuildNode = shouldBuildNode || supportedNodeTargets.some(node => taskDef.execution.hasOwnProperty(node));
        }
        else {
            outDir = path.join(buildPath, path.basename(taskPath));
        }

        mkdir('-p', outDir);

        // get externals
        var taskMakePath = path.join(taskPath, 'make.json');
        var taskMake = test('-f', taskMakePath) ? fileToJson(taskMakePath) : {};
        if (taskMake.hasOwnProperty('externals')) {
            console.log('');
            console.log('> getting task externals');
            getExternals(taskMake.externals, outDir);
        }

        //--------------------------------
        // Common: build, copy, install
        //--------------------------------
        var commonPacks = [];
        if (taskMake.hasOwnProperty('common')) {
            var common = taskMake['common'];

            common.forEach(function(mod) {
                var modPath = path.join(taskPath, mod['module']);
                var modName = path.basename(modPath);
                var modOutDir = path.join(commonPath, modName);

                if (!test('-d', modOutDir)) {
                    banner('Building module ' + modPath, true);

                    mkdir('-p', modOutDir);

                    // create loc files
                    var modJsonPath = path.join(modPath, 'module.json');
                    if (test('-f', modJsonPath)) {
                        createResjson(fileToJson(modJsonPath), modPath);
                    }

                    // npm install and compile
                    if ((mod.type === 'node' && mod.compile == true) || test('-f', path.join(modPath, 'tsconfig.json'))) {
                        buildNodeTask(modPath, modOutDir);
                    }

                    // copy default resources and any additional resources defined in the module's make.json
                    console.log();
                    console.log('> copying module resources');
                    var modMakePath = path.join(modPath, 'make.json');
                    var modMake = test('-f', modMakePath) ? fileToJson(modMakePath) : {};
                    copyTaskResources(modMake, modPath, modOutDir);

                    // get externals
                    if (modMake.hasOwnProperty('externals')) {
                        console.log('');
                        console.log('> getting module externals');
                        getExternals(modMake.externals, modOutDir);
                    }

                    if (mod.type === 'node' && mod.compile == true || test('-f', path.join(modPath, 'package.json'))) {
                        var commonPack = util.getCommonPackInfo(modOutDir);

                        // assert the pack file does not already exist (name should be unique)
                        if (test('-f', commonPack.packFilePath)) {
                            fail(`Pack file already exists: ${commonPack.packFilePath}`);
                        }

                        // pack the Node module. a pack file is required for dedupe.
                        // installing from a folder creates a symlink, and does not dedupe.
                        cd(path.dirname(modOutDir));
                        run(`npm pack ./${path.basename(modOutDir)}`);
                    }
                }

                // store the npm pack file info
                if (mod.type === 'node' && mod.compile == true) {
                    commonPacks.push(util.getCommonPackInfo(modOutDir));
                }
                // copy ps module resources to the task output dir
                else if (mod.type === 'ps') {
                    console.log();
                    console.log('> copying ps module to task');
                    var dest;
                    if (mod.hasOwnProperty('dest')) {
                        dest = path.join(outDir, mod.dest, modName);
                    }
                    else {
                        dest = path.join(outDir, 'ps_modules', modName);
                    }

                    matchCopy('!Tests', modOutDir, dest, { noRecurse: true, matchBase: true });
                }
            });

            // npm install the common modules to the task dir
            if (commonPacks.length) {
                cd(taskPath);
                var installPaths = commonPacks.map(function (commonPack) {
                    return `file:${path.relative(taskPath, commonPack.packFilePath)}`;
                });
                run(`npm install --save-exact ${installPaths.join(' ')}`);
            }
        }

        // build Node task
        if (shouldBuildNode) {
            buildNodeTask(taskPath, outDir);
        }

        // remove the hashes for the common packages, they change every build
        if (commonPacks.length) {
            var lockFilePath = path.join(taskPath, 'package-lock.json');
            if (!test('-f', lockFilePath)) {
                lockFilePath = path.join(taskPath, 'npm-shrinkwrap.json');
            }
            var packageLock = fileToJson(lockFilePath);
            Object.keys(packageLock.dependencies).forEach(function (dependencyName) {
                commonPacks.forEach(function (commonPack) {
                    if (dependencyName == commonPack.packageName) {
                        delete packageLock.dependencies[dependencyName].integrity;
                    }
                });
            });
            fs.writeFileSync(lockFilePath, JSON.stringify(packageLock, null, '  '));
        }

        // copy default resources and any additional resources defined in the task's make.json
        console.log();
        console.log('> copying task resources');
        copyTaskResources(taskMake, taskPath, outDir);
    });

    banner('Build successful', true);
}