[Node - MirageJS to Swagger-Generator] A script that can sit in the MirageJS-Folder and generate as much documentation as possible out of the factories configuration. Filepaths might need tweaking according to paths. Can be run with `node swagger-generator.js` #MirageJS #JavaScript #Swagger #yml

swagger-generator.js

const fs = require('fs');
const readline = require('readline');
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});
const opt = 'utf8';

const routes = fs.readFileSync('./routes.js', opt);
rl.question('Want to generate Swagger Info Object (y/n)? ', (answer) => {
  if (answer === 'y') {
    startReadingFiles(true);
  } else {
    startReadingFiles(false);
  }
  rl.close();
});

function startReadingFiles(infoObject) {
  fs.readFile('./server.js', opt, (error, serverData) => {
    if (error) return error;
    let fileContent = serverData;
    let modelsStart = fileContent.indexOf('models');
    if (modelsStart === -1) {
      console.error('Couldnt find any model definition in the server.js file');
    } else {
      const models = getModelsAsArray(fileContent, modelsStart);
      if (models) {
        fs.readFile('./factories.js', opt, (error, factoriesData) => {
          if (error) return error;
          writingSwaggerFile(infoObject, models, factoriesData);
        });
      }
    }
  });
}

function writingSwaggerFile(infoObject, models, factoriesData) {
  console.log('>>> CREATING FILE swagger.yml');
  let stream = fs.createWriteStream('./swagger.yml');
  stream.once('open', function(fd) {
    if (infoObject) {
      console.log('>>>>>> WRITING SWAGGER INFO OBJECT');
      stream.write(INFO_OBJECT);
    }
    generateSchematas(models, factoriesData, stream);
    generatePaths(models, stream);
    stream.end();
  });
}

function generateSchematas(models, factoriesData, stream) {
  console.log('>>>>>> CREATING SWAGGER SCHEMATA');
  stream.write(SCHEMATAS);
  console.log('>>>>>> CREATING DEFAULT ERROR SCHEMATA');
  stream.write(SCHEMA_ERROR);
  models.forEach((element) => {
    let fieldNames = analyseFactories(factoriesData, element);
    if (fieldNames !== -1) {
      console.log('>>>>>>>>> WRITING SWAGGER SCHEMA ' + element);
      let els = element + 's';
      let elCamel = element.charAt(0).toUpperCase() + element.slice(1);
      let elCamels = element.charAt(0).toUpperCase() + element.slice(1) + 's';
      let spr = SCHEMA_PLACEHOLDER_REQUIRED.replace('{Placeholder}', elCamel);
      console.log('>>>>>>>>> WRITING SWAGGER SCHEMA REQUIRED FIELDS ');
      stream.write(spr);
      fieldNames.forEach((field) => {
        let f = SCHEMA_PLACEHOLDER_REQUIRED_FIELD.replace(
          '{placeholder}',
          field
        );
        stream.write(f);
      });
      stream.write(SCHEMA_PLACEHOLDER_PROPERTIES);
      console.log('>>>>>>>>> WRITING SWAGGER SCHEMA PROPERTIES FIELDS ');
      fieldNames.forEach((field) => {
        let f = SCHEMA_PLACEHOLDER_PROPERTIES_FIELD.replace(
          '{placeholder}',
          field
        );
        stream.write(f);
      });
      console.log('>>>>>>>>> WRITING SWAGGER SCHEMA ' + els);
      let spl = SCHEMA_PLACEHOLDER_LIST.replace(
        '{Placeholder}',
        elCamel
      ).replace('{Placeholders}', elCamels);
      stream.write(spl);
    }
  });
}

function generatePaths(models, stream) {
  console.log('>>>>>> CREATING SWAGGER PATHS');
  stream.write(PATHS);
  models.forEach((element) => {
    console.log('>>>>>>>>> WRITING SWAGGER PATHS ' + element);
    let els = element + 's';
    let elCamel = element.charAt(0).toUpperCase() + element.slice(1);
    let elCamels = element.charAt(0).toUpperCase() + element.slice(1) + 's';
    let pp = PATHS_PLACEHOLDER.replace(/\{Placeholder\}/g, elCamel)
      .replace(/\{Placeholders\}/g, elCamels)
      .replace(/\{placeholder\}/g, element)
      .replace(/\{placeholders\}/g, els);
    stream.write(pp);
  });
}

function getModelsAsArray(fileContent, modelsStart) {
  console.log('>>> PARSING MODELS FROM server.js');
  let modelsObjectStart = fileContent.indexOf('{', modelsStart);
  let modelsObjectEnd = fileContent.indexOf('}', modelsStart);
  let modelsString = fileContent.slice(modelsObjectStart + 1, modelsObjectEnd);
  let models = modelsString.replace(/ |\n|Model,/g, '').split(':');
  models.pop();
  if (models.length > 0) {
    models = models.sort();
    console.log('>>> FOUND MODELS:');
    models.forEach((element) => {
      console.log('>>>>>> ' + element);
    });
    return models;
  } else {
    console.log('>>> NO MODELS DEFINED');
    return -1;
  }
}

function analyseFactories(fileContent, element) {
  console.log('>>> SEARCHING MODEL ' + element + ' IN factories.js');
  let modelsStart = fileContent.indexOf(element + ':');
  if (modelsStart === -1) {
    console.error(
      'Couldnt find the model ' + element + ' in the factories.js file'
    );
  } else {
    console.log('>>> FOUND MODEL ' + element + ' IN factories.js');
    let modelsObjectStart = fileContent.indexOf('({', modelsStart);
    let modelsObjectEnd = fileContent.indexOf('}),', modelsStart);
    let modelsString = fileContent.slice(
      modelsObjectStart + 2,
      modelsObjectEnd
    );
    let indecisOfFieldNames = [];
    let fieldNames = [];
    let regex = /\s{3}[A-Z|a-z]+[(]{1}[)]{1}/gi;
    let result;
    while ((result = regex.exec(modelsString))) {
      indecisOfFieldNames.push(result.index);
    }
    if (indecisOfFieldNames.length > 0) {
      console.log('>>> FOUND FIELDNAMES:');
      indecisOfFieldNames.forEach((index) => {
        fieldEnd = modelsString.indexOf('()', index);
        fieldStart = index + 3;
        let value = modelsString.slice(fieldStart, fieldEnd);
        console.log('>>>>>> ' + value);
        fieldNames.push(value);
      });
      return fieldNames;
    } else {
      return -1;
    }
  }
}

const INFO_OBJECT = `
openapi: 3.0.0

info:
  title: PWA Aicovo
  description: The OpenAPI Specification (OAS) for the PWA Aicovo project. This API is based on the Miragejs Mockdata Service used in the student project and can be added on or modified.
  version: 1.0.0
  contact:
    name: Nicolas Durant
    email: [email protected]

servers:
  - url: http://localhost:8080/api/v1/
    description: Local Development
  - url: https://pwa-aicovo-dev.web.app/api/v1/
    description: Staging
  - url: https://aicovo.de/api/v1/
    description: Production

`;
const SCHEMATAS = `
components:
  schemas:`;
const SCHEMA_ERROR = `
    Error:
      type: object
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string`;
const SCHEMA_PLACEHOLDER_REQUIRED = `
    {Placeholder}:
        required:`;
const SCHEMA_PLACEHOLDER_REQUIRED_FIELD = `
            - {placeholder}`;
const SCHEMA_PLACEHOLDER_PROPERTIES = `
        properties:`;
const SCHEMA_PLACEHOLDER_PROPERTIES_FIELD = `
          {placeholder}:
              type: string`;
const SCHEMA_PLACEHOLDER_LIST = `
    {Placeholders}:
        type: array
        items:
            $ref: "#/components/schemas/{Placeholder}"`;
const PATHS = `
paths:`;
const PATHS_PLACEHOLDER = `
  /{placeholders}:
      get:
          summary: List all {placeholders}
          operationId: list{Placeholders}
          tags:
              - {placeholders}
          parameters:
              - name: limit
                in: query
                description: How many items to return at one time (max 100)
                required: false
                schema:
                      type: integer
                      format: int32
          responses:
              "200":
                  description: A paged array of {placeholders}
                  headers:
                      x-next:
                        description: A link to the next page of responses
                        schema:
                            type: string
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/{Placeholders}"
              default:
                  description: unexpected error
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/Error"
      post:
          summary: Create an {placeholder}
          operationId: create{Placeholders}
          tags:
              - {placeholders}
          parameters:
              - name: {placeholder}
                in: path
                required: true
                description: The {placeholder} object
                schema:
                      $ref: "#/components/schemas/{Placeholder}"
          responses:
              "201":
                  description: {Placeholder} created
              default:
                  description: unexpected error
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/Error"
  /{placeholders}/{id}:
      get:
          summary: Info for a specific {placeholder}
          operationId: show{Placeholder}ById
          tags:
              - {placeholders}
          parameters:
              - name: id
                in: path
                required: true
                description: The id of the {placeholder} to retrieve
                schema:
                      type: integer
                      format: int64
          responses:
              "200":
                  description: {Placeholder} retrieved
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/{Placeholder}"
              default:
                  description: unexpected error
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/Error"
      put:
          summary: Update an {placeholder}
          operationId: update{Placeholders}
          tags:
              - {placeholders}
          parameters:
              - name: id
                in: path
                description: ID of {placeholder} to delete
                required: true
                schema:
                      type: integer
                      format: int64
              - name: {placeholder}
                in: header
                required: true
                description: The {placeholder} object
                schema:
                      $ref: "#/components/schemas/{Placeholder}"
          responses:
              "201":
                  description: {Placeholder} updated
              default:
                  description: unexpected error
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/Error"
      delete:
          summary: Deletes a single {placeholder}
          operationId: delete{Placeholder}
          tags:
              - {placeholders}
          parameters:
              - name: id
                in: path
                description: ID of {placeholder} to delete
                required: true
                schema:
                      type: integer
                      format: int64
          responses:
              "204":
                  description: {Placeholder} deleted
              default:
                  description: unexpected error
                  content:
                      application/json:
                        schema:
                            $ref: "#/components/schemas/Error"`;