feat: scalars functionality (#727)

Pozdro @dweller23

generateModule.js

@@ -9,6 +9,7 @@ const getModuleInfos = require('./parse-graphql/getModuleInfos');
 const getModuleNames = require('./parse-graphql/getModuleNames');
 const getFederatedEntities = require('./parse-graphql/getFederatedEntities');
 const getInterfaces = require('./parse-graphql/getInterfaces');
+const getScalars = require('./parse-graphql/getScalars');
 // const checkIfGitStateClean = require('./helpers/checkIfGitStateClean');
 const saveRenderedTemplate = require('./helpers/saveRenderedTemplate');
 
@@ -405,6 +406,29 @@ const execute = (appPrefix = '@app', generatedPrefix = '@generated', modulesPath
           }
         });
       }
+
+      const scalars = getScalars(schemaString);
+
+      const createScalarResolvers = () => {
+        if (scalars && scalars.length) {
+          shelljs.mkdir('-p', `${projectMainPath}/src/${graphqlFileRootPath}/scalars/`);
+        }
+        scalars.forEach((scalarName) => {
+          const templateName = './templates/scalarResolver.handlebars';
+          const context = {
+            scalarName,
+            moduleName: name,
+            generatedPrefix,
+          };
+          const filePath = `${projectMainPath}/src/${graphqlFileRootPath}/scalars/`;
+          const fileName = `${scalarName}.ts`;
+          const keepIfExists = true;
+
+          saveRenderedTemplate(templateName, context, filePath, fileName, keepIfExists);
+        });
+      };
+      createScalarResolvers();
+
       const moduleName = name;
       const createModuleResolvers = () => {
         const templateName = './templates/moduleResolvers.handlebars';
@@ -415,6 +439,7 @@ const execute = (appPrefix = '@app', generatedPrefix = '@generated', modulesPath
           typeResolvers,
           graphqlFileRootPath,
           appPrefix,
+          scalars,
         };
         const filePath = `${projectMainPath}/generated/graphql/`;
         const fileName = `${moduleName}Resolvers.ts`;

helpers/saveRenderedTemplate.js

@@ -4,8 +4,13 @@ const path = require('path');
 
 Handlebars.registerHelper('toUpperCase', function(str) {
   return str.replace(/^\w/, c => c.toUpperCase());
+})
+
+Handlebars.registerHelper('toLowerCase', function(str) {
+  return str.replace(/^\w/, c => c.toLowerCase());
 });
 
+
 module.exports = function saveRenderedTemplate (templateName, context, filePath, fileName, keepIfExists = false) {
   const combinedPath = path.join(filePath, fileName);
   if (keepIfExists && fs.existsSync(combinedPath)) {

parse-graphql/getScalars.js

@@ -0,0 +1,8 @@
+const gql = require('graphql-tag');
+module.exports = (graphqlString) => {
+  const graphqlAST = gql`
+    ${graphqlString}
+  `;
+
+  return graphqlAST.definitions.filter((d) => d.kind === 'ScalarTypeDefinition').map((f) => f.name.value);
+};

parse-graphql/getScalars.spec.js

@@ -0,0 +1,27 @@
+const getScalars = require('./getScalars');
+const gql = (a) => a[0];
+
+test('get the non extended types with apollo key annotation', () => {
+  const schemaString = gql`
+    type TodoItem @key(fields: "id") {
+      id: ID!
+      list: List
+    }
+
+    extend type List {
+      id: ID!
+      todos: [TodoItem!]!
+      incompleteCount: Int!
+    }
+
+    type InMemory {
+      id: ID!
+    }
+
+    scalar MyOwn
+  `;
+
+  const res = getScalars(schemaString);
+
+  expect(res).toEqual(['MyOwn']);
+});

templates/moduleResolvers.handlebars

@@ -1,6 +1,7 @@
 import {Resolvers} from "./types";
 {{#each queries}}import { {{name}}Query } from "{{../appPrefix}}/{{../graphqlFileRootPath}}queries/{{name}}Query";{{/each}}
 {{#each mutations}}import { {{name}}Mutation } from "{{../appPrefix}}/{{../graphqlFileRootPath}}mutations/{{name}}Mutation";{{/each}}
+{{#each scalars}}import { {{this}} } from "{{../appPrefix}}/{{../graphqlFileRootPath}}scalars/{{this}}";{{/each}}
 {{#each typeResolvers}}{{#each fieldName}}import { {{../typeName}}{{capitalizedName}} } from "{{../../appPrefix}}/{{../../graphqlFileRootPath}}/types/{{../typeName}}{{capitalizedName}}";{{/each}}{{/each}}
 
 // Warning, this file is autogenerated, please don't change it manually.
@@ -11,4 +12,7 @@ export const {{moduleName}}Resolvers: Resolvers = {
     {{typeName}}: { {{#each fieldName}}{{name}}: {{../typeName}}{{capitalizedName}},{{/each}} }, {{/each}}
 {{#if queries.length}}Query: { {{#each queries}}{{name}}: {{name}}Query,{{/each}} },{{/if}}
 {{#if mutations.length}}Mutation: { {{#each mutations}}{{name}}: {{name}}Mutation,{{/each}} },{{/if}}
+{{#if scalars.length}}// Scalars:{{/if}}
+ {{#each scalars}}{{this}},{{/each}}
+
 };

templates/scalarResolver.handlebars

@@ -0,0 +1,8 @@
+import { GraphQLScalarType } from "graphql";
+
+const {{toLowerCase scalarName}}Serialize = (value) => value || null;
+
+export const {{scalarName}}: GraphQLScalarType = new GraphQLScalarType({
+name: "{{scalarName}}",
+serialize: {{toLowerCase scalarName}}Serialize,
+});