node-plop/src/generator-runner.js

programmatic plopping for fun and profit

"use strict";

import promptBypass from "./prompt-bypass.js";
import * as buildInActions from "./actions/index.js";

export default function (plopfileApi, flags) {
  let abort;

  // triggers inquirer with the correct prompts for this generator
  // returns a promise that resolves with the user's answers
  const runGeneratorPrompts = async function (genObject, bypassArr = []) {
    const { prompts } = genObject;

    if (prompts == null) {
      throw Error(`${genObject.name} has no prompts`);
    }

    if (typeof prompts === "function") {
      return await prompts(plopfileApi.inquirer);
    }

    // handle bypass data when provided
    const [promptsAfterBypass, bypassAnswers] = await promptBypass(
      prompts,
      bypassArr,
      plopfileApi,
    );

    return await plopfileApi.inquirer
      .prompt(promptsAfterBypass)
      .then((answers) => Object.assign(answers, bypassAnswers));
  };

  // Run the actions for this generator
  const runGeneratorActions = async function (
    genObject,
    data = {},
    hooks = {},
  ) {
    const noop = () => {};
    const {
      onSuccess = noop, // runs after each successful action
      onFailure = noop, // runs after each failed action
      onComment = noop, // runs for each comment line in the actions array
    } = hooks;
    const changes = []; // array of changed made by the actions
    const failures = []; // array of actions that failed
    let { actions } = genObject; // the list of actions to execute
    const customActionTypes = getCustomActionTypes();
    const actionTypes = Object.assign({}, customActionTypes, buildInActions);

    abort = false;

    // if action is a function, run it to get our array of actions
    if (typeof actions === "function") {
      actions = actions(data);
    }

    // if actions are not defined... we cannot proceed.
    if (actions == null) {
      throw Error(`${genObject.name} has no actions`);
    }

    // if actions are not an array, invalid!
    if (!Array.isArray(actions)) {
      throw Error(`${genObject.name} has invalid actions`);
    }

    for (let [actionIdx, action] of actions.entries()) {
      // including strings in the actions array is used for commenting
      if (typeof action === "string" && abort) {
        continue;
      }
      if (typeof action === "string") {
        onComment(action);
        continue;
      }

      const actionIsFunction = typeof action === "function";
      const actionCfg = actionIsFunction ? { type: "function" } : action;
      const actionLogic = actionIsFunction
        ? action
        : actionTypes[actionCfg.type];

      // bail out if a previous action aborted
      if (abort) {
        const failure = {
          type: actionCfg.type || "",
          path: actionCfg.path || "",
          error: "Aborted due to previous action failure",
        };
        onFailure(failure);
        failures.push(failure);
        continue;
      }

      actionCfg.force = flags.force === true || actionCfg.force === true;

      if (typeof actionLogic !== "function") {
        if (actionCfg.abortOnFail !== false) {
          abort = true;
        }
        const failure = {
          type: actionCfg.type || "",
          path: actionCfg.path || "",
          error: `Invalid action (#${actionIdx + 1})`,
        };
        onFailure(failure);
        failures.push(failure);
        continue;
      }

      try {
        const actionResult = await executeActionLogic(
          actionLogic,
          actionCfg,
          data,
        );
        onSuccess(actionResult);
        changes.push(actionResult);
      } catch (failure) {
        if (actionCfg.abortOnFail !== false) {
          abort = true;
        }
        onFailure(failure);
        failures.push(failure);
      }
    }

    return { changes, failures };
  };

  // handle action logic
  const executeActionLogic = async function (action, cfg, data) {
    const type = cfg.type || "";

    let cfgData = cfg.data || {};
    // data can also be a function that returns a data object
    if (typeof cfgData === "function") {
      cfgData = await cfgData();
    }

    // check if action should run
    if (typeof cfg.skip === "function") {
      // Merge main data and config data in new object
      const reasonToSkip = await cfg.skip({ ...data, ...cfgData });

      if (typeof reasonToSkip === "string") {
        // Return actionResult instead of string
        return {
          type: "skip",
          path: reasonToSkip,
        };
      }
    }

    // track keys that can be applied to the main data scope
    const cfgDataKeys = Object.keys(cfgData).filter(
      (k) => typeof data[k] === "undefined",
    );
    // copy config data into main data scope so it's available for templates
    cfgDataKeys.forEach((k) => {
      data[k] = cfgData[k];
    });

    return await Promise.resolve(action(data, cfg, plopfileApi))
      .then(
        // show the resolved value in the console
        (result) => ({
          type,
          path: typeof result === "string" ? result : JSON.stringify(result),
        }),

        // a rejected promise is treated as a failure
        (err) => {
          throw { type, path: "", error: err.message || err.toString() };
        },
      )
      // cleanup main data scope so config data doesn't leak
      .finally(() =>
        cfgDataKeys.forEach((k) => {
          delete data[k];
        }),
      );
  };

  // request the list of custom actions from the plopfile
  function getCustomActionTypes() {
    return plopfileApi.getActionTypeList().reduce(function (types, name) {
      types[name] = plopfileApi.getActionType(name);
      return types;
    }, {});
  }

  return {
    runGeneratorActions,
    runGeneratorPrompts,
  };
}