[Resolver] add comments. (#78301) (#78333)

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Author: Robert Austin

x-pack/plugins/security_solution/common/endpoint/models/event.ts

@@ -104,6 +104,9 @@ export function timestampAsDateSafeVersion(event: TimestampFields): Date | undef
   }
 }
 
+/**
+ * The @timestamp ECS field
+ */
 export function eventTimestamp(event: SafeResolverEvent): string | undefined | number {
   return firstNonNullValue(event['@timestamp']);
 }
@@ -213,12 +216,18 @@ export function eventSequence(event: EventSequenceFields): number | undefined {
   return firstNonNullValue(event.event?.sequence);
 }
 
+/**
+ * The event.id ECS field.
+ */
 export function eventIDSafeVersion(event: SafeResolverEvent): number | undefined | string {
   return firstNonNullValue(
     isLegacyEventSafeVersion(event) ? event.endgame?.serial_event_id : event.event?.id
   );
 }
 
+/**
+ * The event.entity_id field.
+ */
 export function entityId(event: ResolverEvent): string {
   if (isLegacyEvent(event)) {
     return event.endgame.unique_pid ? String(event.endgame.unique_pid) : '';
@@ -258,6 +267,9 @@ export function entityIDSafeVersion(event: EntityIDFields): string | undefined {
   }
 }
 
+/**
+ * The process.parent.entity_id ECS field.
+ */
 export function parentEntityId(event: ResolverEvent): string | undefined {
   if (isLegacyEvent(event)) {
     return event.endgame.unique_ppid ? String(event.endgame.unique_ppid) : undefined;

x-pack/plugins/security_solution/public/resolver/store/data/selectors.ts

@@ -274,7 +274,7 @@ export const relatedEventCountByType: (
       const stats = statsMap(nodeID);
       if (stats) {
         const value = Object.prototype.hasOwnProperty.call(stats.events.byCategory, eventType);
-        if (typeof value === 'number') {
+        if (typeof value === 'number' && Number.isFinite(value)) {
           return value;
         }
       }

x-pack/plugins/security_solution/public/resolver/view/panels/styles.tsx

@@ -11,20 +11,32 @@ import { EuiBreadcrumbs } from '@elastic/eui';
 import styled from 'styled-components';
 import { EuiDescriptionList } from '@elastic/eui';
 
+/**
+ * Used by the nodeDetail view to show attributes of the related events.
+ */
 export const StyledDescriptionList = styled(EuiDescriptionList)`
   &.euiDescriptionList.euiDescriptionList--column dt.euiDescriptionList__title.desc-title {
     max-width: 10em;
   }
 `;
 
+/**
+ * Used by the nodeDetail view for the label of the node.
+ */
 export const StyledTitle = styled('h4')`
   overflow-wrap: break-word;
 `;
 
+/**
+ * Used for a 'BETA' badge in the breadcrumbs of each panel.
+ */
 export const BetaHeader = styled(`header`)`
   margin-bottom: 1em;
 `;
 
+/**
+ * Styled version of EuiBreadcrumbs that is used by the breadcrumbs in each panel.
+ */
 export const ThemedBreadcrumbs = styled(EuiBreadcrumbs)<{ background: string; text: string }>`
   &.euiBreadcrumbs {
     background-color: ${(props) => props.background};
@@ -38,20 +50,32 @@ export const ThemedBreadcrumbs = styled(EuiBreadcrumbs)<{ background: string; te
   }
 `;
 
+/**
+ * Used in the links to nodes on the node list panel.
+ */
 export const StyledButtonTextContainer = styled.div`
   align-items: center;
   display: flex;
   flex-direction: row;
 `;
 
+/**
+ * Used in the node list panel to call out the event that is represented by the databaseDocumentID.
+ */
 export const StyledAnalyzedEvent = styled.div`
   color: ${(props) => props.color};
   font-size: 10.5px;
   font-weight: 700;
 `;
 
+/**
+ * Used to style the node name in the node list panel view.
+ */
 export const StyledLabelTitle = styled.div``;
 
+/**
+ * Used by the node list view. Wraps the title of the node and the 'Analyzed event' marker.
+ */
 export const StyledLabelContainer = styled.div`
   display: inline-block;
   flex: 3;