created pending and failure module

scm-ui/src/modules/failure.js

@@ -0,0 +1,65 @@
+// @flow
+import type { Action } from "../types/Action";
+
+const FAILURE_SUFFIX = "_FAILURE";
+const RESET_PATTERN = /^(.*)_(SUCCESS|RESET)$/;
+
+function extractIdentifierFromFailure(action: Action) {
+  const type = action.type;
+  let identifier = type.substring(0, type.length - FAILURE_SUFFIX.length);
+  if (action.itemId) {
+    identifier += "/" + action.itemId;
+  }
+  return identifier;
+}
+
+function removeFromState(state: Object, identifier: string) {
+  const newState = {};
+  for (let failureType in state) {
+    if (failureType !== identifier) {
+      newState[failureType] = state[failureType];
+    }
+  }
+  return newState;
+}
+
+export default function reducer(state: Object = {}, action: Action): Object {
+  const type = action.type;
+  if (type.endsWith(FAILURE_SUFFIX)) {
+    const identifier = extractIdentifierFromFailure(action);
+    let payload;
+    if (action.payload instanceof Error) {
+      payload = action.payload;
+    } else if (action.payload) {
+      payload = action.payload.error;
+    }
+    return {
+      ...state,
+      [identifier]: payload
+    };
+  } else {
+    const match = RESET_PATTERN.exec(type);
+    if (match) {
+      let identifier = match[1];
+      if (action.itemId) {
+        identifier += "/" + action.itemId;
+      }
+      return removeFromState(state, identifier);
+    }
+  }
+  return state;
+}
+
+export function getFailure(
+  state: Object,
+  actionType: string,
+  itemId?: string | number
+) {
+  if (state.failure) {
+    let identifier = actionType;
+    if (itemId) {
+      identifier += "/" + itemId;
+    }
+    return state.failure[identifier];
+  }
+}