refactor: better type safety

frontend/src/component/changeRequest/ChangeRequest/Changes/Change/ConsolidatedProgressionChanges.tsx

@@ -15,7 +15,10 @@ import {
     Deleted,
 } from './Change.styles.tsx';
 import type { ChangeMilestoneProgressionSchema } from 'openapi';
-import { MilestoneListRenderer } from './MilestoneListRenderer.tsx';
+import {
+    ReadonlyMilestoneListRenderer,
+    EditableMilestoneListRenderer,
+} from './MilestoneListRenderer.tsx';
 import { applyProgressionChanges } from './applyProgressionChanges.js';
 import { EventDiff } from 'component/events/EventDiff/EventDiff';
 
@@ -72,11 +75,11 @@ export const ConsolidatedProgressionChanges: FC<{
     feature: IChangeRequestFeature;
     currentReleasePlan?: IReleasePlan;
     changeRequestState: ChangeRequestState;
-    onUpdateChangeRequestSubmit?: (
+    onUpdateChangeRequestSubmit: (
         sourceMilestoneId: string,
         payload: ChangeMilestoneProgressionSchema,
     ) => Promise<void>;
-    onDeleteChangeRequestSubmit?: (sourceMilestoneId: string) => Promise<void>;
+    onDeleteChangeRequestSubmit: (sourceMilestoneId: string) => Promise<void>;
 }> = ({
     feature,
     currentReleasePlan,
@@ -113,6 +116,9 @@ export const ConsolidatedProgressionChanges: FC<{
         basePlan,
     );
 
+    const readonly =
+        changeRequestState === 'Applied' || changeRequestState === 'Cancelled';
+
     return (
         <StyledTabs>
             <ChangeItemWrapper>
@@ -137,9 +143,17 @@ export const ConsolidatedProgressionChanges: FC<{
                 </div>
             </ChangeItemWrapper>
             <TabPanel>
-                <MilestoneListRenderer
+                {readonly ? (
+                    <ReadonlyMilestoneListRenderer
+                        plan={modifiedPlan}
+                        milestonesWithAutomation={milestonesWithAutomation}
+                        milestonesWithDeletedAutomation={
+                            milestonesWithDeletedAutomation
+                        }
+                    />
+                ) : (
+                    <EditableMilestoneListRenderer
                         plan={modifiedPlan}
-                    changeRequestState={changeRequestState}
                         milestonesWithAutomation={milestonesWithAutomation}
                         milestonesWithDeletedAutomation={
                             milestonesWithDeletedAutomation
@@ -147,6 +161,7 @@ export const ConsolidatedProgressionChanges: FC<{
                         onUpdateAutomation={onUpdateChangeRequestSubmit}
                         onDeleteAutomation={onDeleteChangeRequestSubmit}
                     />
+                )}
             </TabPanel>
             <TabPanel variant='diff'>
                 <EventDiff

frontend/src/component/changeRequest/ChangeRequest/Changes/Change/MilestoneListRenderer.tsx

@@ -1,7 +1,6 @@
 import { styled } from '@mui/material';
 import type { IReleasePlan } from 'interfaces/releasePlans';
 import type { ChangeMilestoneProgressionSchema } from 'openapi';
-import type { ChangeRequestState } from 'component/changeRequest/changeRequest.types';
 import { ReleasePlanMilestone } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestone/ReleasePlanMilestone';
 import { MilestoneAutomationSection } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestone/MilestoneAutomationSection.tsx';
 import { MilestoneTransitionDisplay } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestone/MilestoneTransitionDisplay.tsx';
@@ -15,29 +14,26 @@ const StyledConnection = styled('div')(({ theme }) => ({
     marginLeft: theme.spacing(3.25),
 }));
 
-interface MilestoneListRendererProps {
+interface MilestoneListRendererCoreProps {
     plan: IReleasePlan;
-    changeRequestState: ChangeRequestState;
+    readonly: boolean;
-    milestonesWithAutomation?: Set<string>;
+    milestonesWithAutomation: Set<string>;
-    milestonesWithDeletedAutomation?: Set<string>;
+    milestonesWithDeletedAutomation: Set<string>;
-    onUpdateAutomation?: (
+    onUpdateAutomation: (
         sourceMilestoneId: string,
         payload: ChangeMilestoneProgressionSchema,
     ) => Promise<void>;
-    onDeleteAutomation?: (sourceMilestoneId: string) => void;
+    onDeleteAutomation: (sourceMilestoneId: string) => void;
 }
 
-export const MilestoneListRenderer = ({
+const MilestoneListRendererCore = ({
     plan,
-    changeRequestState,
+    readonly,
-    milestonesWithAutomation = new Set(),
+    milestonesWithAutomation,
-    milestonesWithDeletedAutomation = new Set(),
+    milestonesWithDeletedAutomation,
     onUpdateAutomation,
     onDeleteAutomation,
-}: MilestoneListRendererProps) => {
+}: MilestoneListRendererCoreProps) => {
-    // TODO: Split into read and write model at the type level to avoid having optional handlers
-    const readonly =
-        changeRequestState === 'Applied' || changeRequestState === 'Cancelled';
     const status: MilestoneStatus = 'not-started';
 
     return (
@@ -70,14 +66,14 @@ export const MilestoneListRenderer = ({
                                 }
                                 targetMilestoneId={nextMilestoneId}
                                 onSave={async (payload) => {
-                                    await onUpdateAutomation?.(
+                                    await onUpdateAutomation(
                                         milestone.id,
                                         payload,
                                     );
                                     return { shouldReset: true };
                                 }}
                                 onDelete={() =>
-                                    onDeleteAutomation?.(milestone.id)
+                                    onDeleteAutomation(milestone.id)
                                 }
                                 milestoneName={milestone.name}
                                 status={status}
@@ -102,3 +98,56 @@ export const MilestoneListRenderer = ({
         </>
     );
 };
+
+interface ReadonlyMilestoneListRendererProps {
+    plan: IReleasePlan;
+    milestonesWithAutomation?: Set<string>;
+    milestonesWithDeletedAutomation?: Set<string>;
+}
+
+export const ReadonlyMilestoneListRenderer = ({
+    plan,
+    milestonesWithAutomation = new Set(),
+    milestonesWithDeletedAutomation = new Set(),
+}: ReadonlyMilestoneListRendererProps) => {
+    return (
+        <MilestoneListRendererCore
+            plan={plan}
+            readonly={true}
+            milestonesWithAutomation={milestonesWithAutomation}
+            milestonesWithDeletedAutomation={milestonesWithDeletedAutomation}
+            onUpdateAutomation={async () => {}}
+            onDeleteAutomation={() => {}}
+        />
+    );
+};
+
+interface EditableMilestoneListRendererProps {
+    plan: IReleasePlan;
+    milestonesWithAutomation?: Set<string>;
+    milestonesWithDeletedAutomation?: Set<string>;
+    onUpdateAutomation: (
+        sourceMilestoneId: string,
+        payload: ChangeMilestoneProgressionSchema,
+    ) => Promise<void>;
+    onDeleteAutomation: (sourceMilestoneId: string) => void;
+}
+
+export const EditableMilestoneListRenderer = ({
+    plan,
+    milestonesWithAutomation = new Set(),
+    milestonesWithDeletedAutomation = new Set(),
+    onUpdateAutomation,
+    onDeleteAutomation,
+}: EditableMilestoneListRendererProps) => {
+    return (
+        <MilestoneListRendererCore
+            plan={plan}
+            readonly={false}
+            milestonesWithAutomation={milestonesWithAutomation}
+            milestonesWithDeletedAutomation={milestonesWithDeletedAutomation}
+            onUpdateAutomation={onUpdateAutomation}
+            onDeleteAutomation={onDeleteAutomation}
+        />
+    );
+};

frontend/src/component/changeRequest/ChangeRequest/Changes/Change/ProgressionChange.tsx

@@ -10,7 +10,10 @@ import { EventDiff } from 'component/events/EventDiff/EventDiff';
 import { Tab, TabList, TabPanel, Tabs } from './ChangeTabComponents.tsx';
 import { Action, ChangeItemInfo, ChangeItemWrapper } from './Change.styles.tsx';
 import { styled } from '@mui/material';
-import { MilestoneListRenderer } from './MilestoneListRenderer.tsx';
+import {
+    ReadonlyMilestoneListRenderer,
+    EditableMilestoneListRenderer,
+} from './MilestoneListRenderer.tsx';
 import { applyProgressionChanges } from './applyProgressionChanges.ts';
 
 const StyledTabs = styled(Tabs)(({ theme }) => ({
@@ -24,11 +27,11 @@ interface ProgressionChangeProps {
     currentReleasePlan?: IReleasePlan;
     actions?: ReactNode;
     changeRequestState: ChangeRequestState;
-    onUpdateChangeRequestSubmit?: (
+    onUpdateChangeRequestSubmit: (
         sourceMilestoneId: string,
         payload: ChangeMilestoneProgressionSchema,
     ) => Promise<void>;
-    onDeleteChangeRequestSubmit?: (sourceMilestoneId: string) => void;
+    onDeleteChangeRequestSubmit: (sourceMilestoneId: string) => void;
 }
 
 export const ProgressionChange: FC<ProgressionChangeProps> = ({
@@ -62,6 +65,9 @@ export const ProgressionChange: FC<ProgressionChangeProps> = ({
         (milestone) => milestone.id === sourceId,
     );
 
+    const readonly =
+        changeRequestState === 'Applied' || changeRequestState === 'Cancelled';
+
     return (
         <StyledTabs>
             <ChangeItemWrapper>
@@ -80,15 +86,23 @@ export const ProgressionChange: FC<ProgressionChangeProps> = ({
                 </div>
             </ChangeItemWrapper>
             <TabPanel>
-                <MilestoneListRenderer
+                {readonly ? (
+                    <ReadonlyMilestoneListRenderer
+                        plan={modifiedPlan}
+                        milestonesWithAutomation={
+                            new Set([sourceId].filter(Boolean))
+                        }
+                    />
+                ) : (
+                    <EditableMilestoneListRenderer
                         plan={modifiedPlan}
-                    changeRequestState={changeRequestState}
                         milestonesWithAutomation={
                             new Set([sourceId].filter(Boolean))
                         }
                         onUpdateAutomation={onUpdateChangeRequestSubmit}
                         onDeleteAutomation={onDeleteChangeRequestSubmit}
                     />
+                )}
             </TabPanel>
             <TabPanel variant='diff'>
                 <EventDiff

frontend/src/component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestoneItem/ReleasePlanMilestoneItem.tsx

@@ -8,7 +8,7 @@ import { useChangeRequestsEnabled } from 'hooks/useChangeRequestsEnabled';
 import useToast from 'hooks/useToast';
 import { formatUnknownError } from 'utils/formatUnknownError';
 import { calculateMilestoneStatus } from './milestoneStatusUtils.js';
-import { usePendingProgressionChanges } from './usePendingProgressionChanges.js';
+import { getPendingProgressionData } from './pendingProgressionChanges.js';
 import { MilestoneAutomation } from './MilestoneAutomation.tsx';
 
 const StyledConnection = styled('div', {
@@ -130,7 +130,7 @@ export const ReleasePlanMilestoneItem = ({
     );
 
     const { pendingProgressionChange, effectiveTransitionCondition } =
-        usePendingProgressionChanges(milestone, getPendingProgressionChange);
+        getPendingProgressionData(milestone, getPendingProgressionChange);
 
     const shouldShowAutomation =
         isNotLastMilestone && milestoneProgressionsEnabled;

frontend/src/component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestoneItem/pendingProgressionChanges.ts

@@ -9,7 +9,7 @@ interface PendingProgressionChangeResult {
     effectiveTransitionCondition: IReleasePlanMilestone['transitionCondition'];
 }
 
-export const usePendingProgressionChanges = (
+export const getPendingProgressionData = (
     milestone: IReleasePlanMilestone,
     getPendingProgressionChange: IReleasePlanMilestoneItemProps['getPendingProgressionChange'],
 ): PendingProgressionChangeResult => {