Add test to compile typescript-yoga template

packages/graphqlgen/package.json

@@ -62,6 +62,7 @@
     "jest": "23.6.0",
     "ts-jest": "23.10.4",
     "ts-node": "7.0.1",
-    "tslint": "5.11.0"
+    "tslint": "5.11.0",
+    "typescript": "^3.1.6"
   }
 }

packages/graphqlgen/src/tests/typescript-yoga/index.test.ts

@@ -0,0 +1,55 @@
+import * as ts from 'typescript'
+import * as glob from 'glob'
+import { execSync } from 'child_process'
+import { join } from 'path'
+
+const relative = (p: string) => join(__dirname, p)
+
+function printErrors(diagnotics: ReadonlyArray<ts.Diagnostic>) {
+  diagnotics.forEach(diagnostic => {
+    if (diagnostic.file) {
+      let { line, character } = diagnostic.file.getLineAndCharacterOfPosition(
+        diagnostic.start!,
+      )
+      let message = ts.flattenDiagnosticMessageText(
+        diagnostic.messageText,
+        '\n',
+      )
+      console.log(
+        `${diagnostic.file.fileName} (${line + 1},${character +
+          1}): ${message}`,
+      )
+    } else {
+      console.log(
+        `${ts.flattenDiagnosticMessageText(diagnostic.messageText, '\n')}`,
+      )
+    }
+  })
+}
+
+test('compile typescript-yoga', async () => {
+  const typescriptYogaRootDir = relative(
+    '../../../../graphqlgen-templates/typescript-yoga',
+  )
+
+  const fileNames = glob.sync(join(typescriptYogaRootDir, './src/**/*.ts'))
+
+  process.chdir(typescriptYogaRootDir)
+  execSync('yarn install && yarn generate')
+
+  const errors = ts
+    .createProgram(fileNames, {
+      skipLibCheck: true,
+      sourceMap: false,
+      noEmitOnError: true,
+      target: ts.ScriptTarget.ESNext,
+      module: ts.ModuleKind.CommonJS,
+    })
+    .emit().diagnostics
+
+  if (errors.length > 0) {
+    printErrors(errors)
+  }
+
+  expect(errors.length).toEqual(0)
+})