frontend: clean up assertions

Author: kahkeng

frontend/ts/components/TodoList.tsx

@@ -41,12 +41,8 @@ class TodoList extends React.Component<Props> {
     );
   };
   renderTodos() {
-    if (!this.props.viewer.todos || !this.props.viewer.todos.edges) {
-      throw new Error('assertion failed');
-    }
-    return this.props.viewer.todos.edges.map(edge => {
-      const node = edge && edge.node;
-      if (!node) throw new Error('assertion failed');
+    return this.props.viewer.todos!.edges!.map(edge => {
+      const node = edge!.node!;
       return <Todo
         key={node.id}
         todo={node}

frontend/ts/mutations/AddTodoMutation.ts

@@ -66,8 +66,7 @@ function commit(environment: Environment, text: string, user: TodoApp_viewer) {
       },
     },
     updater: store => {
-      const payload = store.getRootField("addTodo")
-      if (!payload) throw new Error("assertion failed")
+      const payload = store.getRootField("addTodo")!
       const newEdge = payload.getLinkedRecord("todoEdge")
       sharedUpdater(store, user, newEdge)
     },
@@ -79,8 +78,7 @@ function commit(environment: Environment, text: string, user: TodoApp_viewer) {
       const newEdge = store.create("client:newEdge:" + tempID++, "TodoEdge")
       newEdge.setLinkedRecord(node, "node")
       sharedUpdater(store, user, newEdge)
-      const userProxy = store.get(user.id)
-      if (!userProxy) throw new Error("assertion failed")
+      const userProxy = store.get(user.id)!
       userProxy.setValue(
         (userProxy.getValue("totalCount") as number) + 1,
         "totalCount",

frontend/ts/mutations/ChangeTodoStatusMutation.ts

@@ -43,8 +43,7 @@ function sharedUpdater(
 ) {
   // In principle this could add to the active connection, but such an
   // interaction is not possible from the front end.
-  const userProxy = store.get(user.id);
-  if (!userProxy) throw new Error("assertion failed")
+  const userProxy = store.get(user.id)!;
   const status = todoProxy.getValue('complete') ? 'active' : 'completed';
   const connection = ConnectionHandler.getConnection(
     userProxy,
@@ -93,8 +92,7 @@ function commit(
       input: { complete, id: todo.id },
     },
     updater: store => {
-      const payload = store.getRootField("changeTodoStatus")
-      if (!payload) throw new Error("assertion failed")
+      const payload = store.getRootField("changeTodoStatus")!
       sharedUpdater(store, user, payload.getLinkedRecord("todo"))
     },
     optimisticResponse: getOptimisticResponse(complete, todo, user),

frontend/ts/mutations/MarkAllTodosMutation.ts

@@ -58,14 +58,12 @@ function commit(
     },
 
     updater: store => {
-      const userProxy = store.get(user.id);
-      if (!userProxy) throw new Error("assertion failed")
+      const userProxy = store.get(user.id)!;
       const connection = ConnectionHandler.getConnection(
         userProxy,
         'TodoList_todos',
         { status },
-      );
-      if (!connection) throw new Error("assertion failed")
+      )!;
       const todoEdges = store
         .getRootField('markAllTodos')
         .getLinkedRecord('viewer')
@@ -75,14 +73,12 @@ function commit(
     },
 
     optimisticUpdater(store) {
-      const userProxy = store.get(user.id);
-      if (!userProxy) throw new Error("assertion failed")
+      const userProxy = store.get(user.id)!;
       const connection = ConnectionHandler.getConnection(
         userProxy,
         'TodoList_todos',
         { status },
-      );
-      if (!connection) throw new Error("assertion failed")
+      )!;
 
       if (
         (complete && status === 'active') ||

frontend/ts/mutations/RemoveCompletedTodosMutation.ts

@@ -60,20 +60,18 @@ function commit(
       input: {},
     },
     updater: store => {
-      const payload = store.getRootField("removeCompletedTodos")
-      if (!payload) throw new Error("assertion failed")
+      const payload = store.getRootField("removeCompletedTodos")!
       sharedUpdater(store, user, payload.getValue("deletedTodoIds") as string[])
     },
     optimisticUpdater: store => {
-      const userProxy = store.get(user.id)
+      const userProxy = store.get(user.id)!
       let deletedIDs
       if (todos && todos.edges) {
         deletedIDs = todos.edges
           .filter(edge => edge && edge.node && edge.node.complete)
           .map(edge => (edge && edge.node && edge.node.id) as string)
         sharedUpdater(store, user, deletedIDs)
       }
-      if (!userProxy) throw new Error("assertion failed")
       const numTodos = (userProxy.getValue('numTodos') as number);
       if (deletedIDs) {
         userProxy.setValue(numTodos - deletedIDs.length, 'numTodos');

frontend/ts/mutations/RemoveTodoMutation.ts

@@ -38,8 +38,7 @@ function sharedUpdater(
   user: Todo_viewer,
   deletedID: string,
 ) {
-  const userProxy = store.get(user.id)
-  if (!userProxy) throw new Error("assertion failed");
+  const userProxy = store.get(user.id)!;
   ['any', 'active', 'completed'].forEach((status) => {
     const conn = ConnectionHandler.getConnection(userProxy, "TodoList_todos", { status })
     if (conn) {
@@ -55,15 +54,13 @@ function commit(environment: Environment, todo: Todo_todo, user: Todo_viewer) {
       input: { id: todo.id },
     },
     updater: store => {
-      const payload = store.getRootField("removeTodo")
-      if (!payload) throw new Error("assertion failed")
+      const payload = store.getRootField("removeTodo")!
       sharedUpdater(store, user, payload.getValue("deletedTodoId") as string)
     },
     optimisticUpdater: store => {
       sharedUpdater(store, user, todo.id)
 
-      const userProxy = store.get(user.id)
-      if (!userProxy) throw new Error("assertion failed")
+      const userProxy = store.get(user.id)!
       const numTodos = userProxy.getValue('numTodos')
       if (numTodos != null) {
         userProxy.setValue((numTodos as number) - 1, 'numTodos')