[sources] update newSources filter check (firefox-devtools#6778)

Author: jasonLaster

src/actions/sources/newSources.js

@@ -51,11 +51,14 @@ function loadSourceMaps(sources) {
       return;
     }
 
-    const originalSources = await Promise.all(
-      sources.map(source => dispatch(loadSourceMap(source.id)))
+    let originalSources = await Promise.all(
+      sources.map(({ id }) => dispatch(loadSourceMap(id)))
     );
 
-    await dispatch(newSources(flatten(originalSources)));
+    originalSources = flatten(originalSources).filter(Boolean);
+    if (originalSources.length > 0) {
+      await dispatch(newSources(originalSources));
+    }
   };
 }
 
@@ -172,30 +175,23 @@ export function newSource(source: Source) {
 
 export function newSources(sources: Source[]) {
   return async ({ dispatch, getState }: ThunkArgs) => {
-    const filteredSources = sources.filter(
-      source => source && !getSource(getState(), source.id)
-    );
+    sources = sources.filter(source => !getSource(getState(), source.id));
 
-    if (filteredSources.length == 0) {
+    if (sources.length == 0) {
       return;
     }
 
-    dispatch(
-      ({
-        type: "ADD_SOURCES",
-        sources: filteredSources
-      }: Action)
-    );
+    dispatch(({ type: "ADD_SOURCES", sources: sources }: Action));
 
-    for (const source of filteredSources) {
+    for (const source of sources) {
       dispatch(checkSelectedSource(source.id));
       dispatch(checkPendingBreakpoints(source.id));
     }
 
-    await dispatch(loadSourceMaps(filteredSources));
+    await dispatch(loadSourceMaps(sources));
 
     // We would like to restore the blackboxed state
     // after loading all states to make sure the correctness.
-    await dispatch(restoreBlackBoxedSources(filteredSources));
+    await dispatch(restoreBlackBoxedSources(sources));
   };
 }