pre-commit warning for large sloc commits

Summary: this diff adds the Split suggestion banner to the commit mode w/ some minor mods to the verbiage to encourage folks to select less files.

Reviewed By: evangrayk

Differential Revision: D58418870

fbshipit-source-id: 458dc9be3f06c7e58799c8acab47c91aa19508f2

addons/isl/src/CommitInfoView/SplitSuggestion.tsx

@@ -12,51 +12,104 @@ import {Divider} from '../components/Divider';
 import GatedComponent from '../components/GatedComponent';
 import {T, t} from '../i18n';
 import {localStorageBackedAtom} from '../jotaiUtils';
+import {uncommittedChangesWithPreviews} from '../previews';
 import {
   MAX_FILES_ALLOWED_FOR_DIFF_STAT,
   SLOC_THRESHOLD_FOR_SPLIT_SUGGESTIONS,
 } from '../sloc/diffStatConstants';
-import {useFetchSignificantLinesOfCode} from '../sloc/useFetchSignificantLinesOfCode';
+import {
+  useFetchPendingSignificantLinesOfCode,
+  useFetchSignificantLinesOfCode,
+} from '../sloc/useFetchSignificantLinesOfCode';
 import {SplitButton} from '../stackEdit/ui/SplitButton';
 import {type CommitInfo} from '../types';
+import {commitMode} from './CommitInfoState';
 import {useAtomValue} from 'jotai';
+import {Suspense} from 'react';
 import {Icon} from 'shared/Icon';
 
 export const splitSuggestionEnabled = localStorageBackedAtom<boolean>(
   'isl.split-suggestion-enabled',
   true,
 );
 
-function SplitSuggestionImpl({commit}: {commit: CommitInfo}) {
-  const significantLinesOfCode = useFetchSignificantLinesOfCode(commit);
-  if (
-    significantLinesOfCode == null ||
-    significantLinesOfCode <= SLOC_THRESHOLD_FOR_SPLIT_SUGGESTIONS
-  ) {
-    return null;
-  }
+function SuggestionBanner({
+  tooltip,
+  buttons,
+  children,
+}: {
+  tooltip: string;
+  buttons?: React.ReactNode;
+  children: React.ReactNode;
+}) {
   return (
     <>
       <Divider />
       <Banner
-        tooltip={t('This commit has $sloc significant lines of code (top 10%)', {
-          replace: {$sloc: String(significantLinesOfCode)},
-        })}
+        tooltip={tooltip}
         kind={BannerKind.default}
         icon={<Icon size="M" icon="lightbulb" color="blue" />}
         alwaysShowButtons
-        buttons={<SplitButton trackerEventName="SplitOpenFromSplitSuggestion" commit={commit} />}>
+        buttons={buttons}>
         <Column alignStart style={{gap: 0}}>
-          <b>
-            <T>Consider splitting up this commit</T>
-          </b>
-          <T>Small Diffs lead to less SEVs & quicker review times</T>
+          {children}
         </Column>
       </Banner>
     </>
   );
 }
 
+function NewCommitSuggestion() {
+  const pendingSignificantLinesOfCode = useFetchPendingSignificantLinesOfCode();
+  if (pendingSignificantLinesOfCode == null) {
+    return null;
+  }
+
+  if (pendingSignificantLinesOfCode > SLOC_THRESHOLD_FOR_SPLIT_SUGGESTIONS) {
+    return (
+      <SuggestionBanner
+        tooltip={t('This commit would have $sloc significant lines of code (top 10%)', {
+          replace: {$sloc: String(pendingSignificantLinesOfCode)},
+        })}>
+        <b>
+          <T>Consider unselecting some of these changes</T>
+        </b>
+        <T>Small Diffs lead to less SEVs & quicker review times</T>
+      </SuggestionBanner>
+    );
+  }
+}
+
+function SplitSuggestionImpl({commit}: {commit: CommitInfo}) {
+  const mode = useAtomValue(commitMode);
+  const significantLinesOfCode = useFetchSignificantLinesOfCode(commit) ?? -1;
+  const uncommittedChanges = useAtomValue(uncommittedChangesWithPreviews);
+
+  // no matter what if the commit is over the threshold, we show the split suggestion
+  if (significantLinesOfCode > SLOC_THRESHOLD_FOR_SPLIT_SUGGESTIONS) {
+    return (
+      <SuggestionBanner
+        tooltip={t('This commit has $sloc significant lines of code (top 10%)', {
+          replace: {$sloc: String(significantLinesOfCode)},
+        })}
+        buttons={<SplitButton trackerEventName="SplitOpenFromSplitSuggestion" commit={commit} />}>
+        <b>
+          <T>Consider splitting up this commit</T>
+        </b>
+        <T>Small Diffs lead to less SEVs & quicker review times</T>
+      </SuggestionBanner>
+    );
+  }
+
+  // if there are uncommitted changes, let's (maybe) show the suggestion to make a new commit
+  if (uncommittedChanges.length > 0 && mode === 'commit') {
+    return <NewCommitSuggestion />;
+  }
+
+  // no need to show any suggestion
+  return null;
+}
+
 export default function SplitSuggestion({commit}: {commit: CommitInfo}) {
   const enabled = useAtomValue(splitSuggestionEnabled);
   if (!enabled || commit.totalFileCount > MAX_FILES_ALLOWED_FOR_DIFF_STAT) {