Use app logic for loading default file in embed

Author: siddharthkp

packages/app/src/embed/components/App/index.js

@@ -225,13 +225,16 @@ export default class App extends React.PureComponent<
   getCurrentModuleFromPath = (sandbox: Sandbox): Module => {
     const { currentModule: currentModulePath } = this.state;
 
-    return (
-      findCurrentModule(
+    return findCurrentModule(
+      sandbox.modules,
+      sandbox.directories,
+      currentModulePath,
+      findMainModule(
         sandbox.modules,
         sandbox.directories,
-        currentModulePath,
-        findMainModule(sandbox.modules, sandbox.directories, sandbox.entry)
-      ) || sandbox.modules[0]
+        sandbox.entry,
+        sandbox.template
+      )
     );
   };
 

packages/app/src/embed/components/Content/index.tsx

@@ -387,7 +387,12 @@ export default class Content extends React.PureComponent<Props, State> {
     } = this.props;
 
     const mainModule = isInProjectView
-      ? findMainModule(sandbox.modules, sandbox.directories, sandbox.entry)
+      ? findMainModule(
+          sandbox.modules,
+          sandbox.directories,
+          sandbox.entry,
+          sandbox.template
+        )
       : currentModule;
 
     if (!mainModule) throw new Error('Cannot find main module');

packages/common/src/sandbox/modules.ts

@@ -1,5 +1,6 @@
 import memoize from 'lodash/memoize';
 import { Module, Directory } from '../types';
+import getTemplateDefinition, { TemplateType } from '../templates';
 
 const compareTitle = (
   original: string,
@@ -251,14 +252,30 @@ export const isMainModule = (
 export const findMainModule = (
   modules: Module[],
   directories: Directory[],
-  entry: string = 'index.js'
+  entry: string = 'index.js',
+  template?: TemplateType
 ) => {
   try {
+    // first attempt: try loading the entry file if it exists
     const module = resolveModule(entry, modules, directories);
-
     return module;
   } catch (e) {
-    return modules[0];
+    try {
+      // second attempt: try loading the first file that exists from
+      // the list of possible defaults in the template defination
+      const templateDefinition = getTemplateDefinition(template);
+
+      const defaultOpenedFiles = templateDefinition.getDefaultOpenedFiles({});
+
+      const defaultOpenModule = defaultOpenedFiles
+        .map(path => resolveModuleWrapped({ modules, directories })(path))
+        .find(module => module);
+
+      return defaultOpenModule;
+    } catch (nestedError) {
+      // third attempt: give up and load the first file in the list
+      return modules[0];
+    }
   }
 };
 
@@ -284,3 +301,19 @@ export const findCurrentModule = (
     mainModule
   );
 };
+
+export const resolveModuleWrapped = sandbox => (path: string) => {
+  try {
+    return resolveModule(path, sandbox.modules, sandbox.directories);
+  } catch (e) {
+    return undefined;
+  }
+};
+
+export const resolveDirectoryWrapped = sandbox => (path: string) => {
+  try {
+    return resolveDirectory(path, sandbox.modules, sandbox.directories);
+  } catch (e) {
+    return undefined;
+  }
+};

packages/common/src/templates/configuration/resolve-module-wrapped.ts

@@ -1,17 +1,10 @@
-import { resolveModule, resolveDirectory } from '../../sandbox/modules';
+import {
+  resolveModuleWrapped,
+  resolveDirectoryWrapped,
+} from '../../sandbox/modules';
 
-export const resolveModuleWrapped = sandbox => (path: string) => {
-  try {
-    return resolveModule(path, sandbox.modules, sandbox.directories);
-  } catch (e) {
-    return undefined;
-  }
-};
+// keeping this file around to reduce merge conflicts
+// with other open branches
+// TODO @sid: Replace the usage of this file after overmind refactor is complete.
 
-export const resolveDirectoryWrapped = sandbox => (path: string) => {
-  try {
-    return resolveDirectory(path, sandbox.modules, sandbox.directories);
-  } catch (e) {
-    return undefined;
-  }
-};
+export { resolveModuleWrapped, resolveDirectoryWrapped };