Prevent unecessary renders (firefox-devtools#4735)

jasonLaster · codehag · commit 7a4628c915ed · 2017-11-20T10:28:42.000+01:00
diff --git a/src/reducers/ast.js b/src/reducers/ast.js
@@ -183,8 +183,9 @@ export function getPreview(state: OuterState) {
   return state.ast.get("preview");
 }
 
+const emptySourceMetaData = {};
 export function getSourceMetaData(state: OuterState, sourceId: string) {
-  return state.ast.getIn(["sourceMetaData", sourceId]) || {};
+  return state.ast.getIn(["sourceMetaData", sourceId]) || emptySourceMetaData;
 }
 
 export default update;

Original file line number	Diff line number	Diff line change
`@@ -183,8 +183,9 @@ export function getPreview(state: OuterState) {`
`183`	`183`	`return state.ast.get("preview");`
`184`	`184`	`}`
`185`	`185`
	`186`	`+const emptySourceMetaData = {};`
`186`	`187`	`export function getSourceMetaData(state: OuterState, sourceId: string) {`
`187`		`- return state.ast.getIn(["sourceMetaData", sourceId]) \|\| {};`
	`188`	`+ return state.ast.getIn(["sourceMetaData", sourceId]) \|\| emptySourceMetaData;`
`188`	`189`	`}`
`189`	`190`
`190`	`191`	`export default update;`