add tabs to milestone start (#10237)

Adds changes/view diff tabs to release plan changes that show diffs. The
only instances I found where we show JSON diffs today was starting
milestones and adding a new release plan if you already have one.

I've moved the old file into a legacy file because we're touching two
out of three internal components, so it seemed like leaving it all in
one file would be a bit of a hassle. plus, this way it's consistent with
segments and strategies.

Start milestone:
<img width="1035" alt="image"
src="https://github.com/user-attachments/assets/2b4616f6-8452-4976-8101-11a94d6d5828"
/>

<img width="1054" alt="image"
src="https://github.com/user-attachments/assets/0ba58c72-b3dc-48fa-95bf-a3980dc620fe"
/>

Plan replacement:
<img width="1006" alt="image"
src="https://github.com/user-attachments/assets/9381a48f-e23e-435e-8fa5-02fcb5050bfd"
/>

<img width="818" alt="image"
src="https://github.com/user-attachments/assets/c5ceb9db-b095-4d05-88e8-fd8a70776479"
/>

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

@@ -14,6 +14,7 @@ import { EnvironmentStrategyExecutionOrder } from './EnvironmentStrategyExecutio
 import { ArchiveFeatureChange } from './ArchiveFeatureChange.tsx';
 import { DependencyChange } from './DependencyChange.tsx';
 import { Link } from 'react-router-dom';
+import { LegacyReleasePlanChange } from './LegacyReleasePlanChange.tsx';
 import { ReleasePlanChange } from './ReleasePlanChange.tsx';
 import { StrategyChange } from './StrategyChange.tsx';
 import { useUiFlag } from 'hooks/useUiFlag.ts';
@@ -94,6 +95,10 @@ export const FeatureChange: FC<{
         ? StrategyChange
         : LegacyStrategyChange;
 
+    const ReleasePlanChangeComponent = useDiffableChangeComponent
+        ? ReleasePlanChange
+        : LegacyReleasePlanChange;
+
     return (
         <StyledSingleChangeBox
             key={objectId(change)}
@@ -204,7 +209,7 @@ export const FeatureChange: FC<{
                 {(change.action === 'addReleasePlan' ||
                     change.action === 'deleteReleasePlan' ||
                     change.action === 'startMilestone') && (
-                    <ReleasePlanChange
+                    <ReleasePlanChangeComponent
                         actions={actions}
                         change={change}
                         featureName={feature.name}

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

@@ -0,0 +1,316 @@
+import type React from 'react';
+import { useRef, useState, type FC, type ReactNode } from 'react';
+import { Box, styled, Typography } from '@mui/material';
+import type {
+    ChangeRequestState,
+    IChangeRequestAddReleasePlan,
+    IChangeRequestDeleteReleasePlan,
+    IChangeRequestStartMilestone,
+} from 'component/changeRequest/changeRequest.types';
+import { useReleasePlanPreview } from 'hooks/useReleasePlanPreview';
+import { useReleasePlans } from 'hooks/api/getters/useReleasePlans/useReleasePlans';
+import { TooltipLink } from 'component/common/TooltipLink/TooltipLink';
+import EventDiff from 'component/events/EventDiff/EventDiff';
+import { ReleasePlan } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlan';
+import { ReleasePlanMilestone } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestone/ReleasePlanMilestone';
+import type { IReleasePlan } from 'interfaces/releasePlans';
+
+export const ChangeItemWrapper = styled(Box)({
+    display: 'flex',
+    justifyContent: 'space-between',
+    alignItems: 'center',
+});
+
+const ChangeItemCreateEditDeleteWrapper = styled(Box)(({ theme }) => ({
+    display: 'grid',
+    gridTemplateColumns: 'auto auto',
+    justifyContent: 'space-between',
+    gap: theme.spacing(1),
+    alignItems: 'center',
+    marginBottom: theme.spacing(2),
+    width: '100%',
+}));
+
+const ChangeItemInfo: FC<{ children?: React.ReactNode }> = styled(Box)(
+    ({ theme }) => ({
+        display: 'flex',
+        gap: theme.spacing(1),
+    }),
+);
+
+const ViewDiff = styled('span')(({ theme }) => ({
+    color: theme.palette.primary.main,
+    marginLeft: theme.spacing(1),
+}));
+
+const StyledCodeSection = styled('div')(({ theme }) => ({
+    overflowX: 'auto',
+    '& code': {
+        wordWrap: 'break-word',
+        whiteSpace: 'pre-wrap',
+        fontFamily: 'monospace',
+        lineHeight: 1.5,
+        fontSize: theme.fontSizes.smallBody,
+    },
+}));
+
+const DeleteReleasePlan: FC<{
+    change: IChangeRequestDeleteReleasePlan;
+    currentReleasePlan?: IReleasePlan;
+    changeRequestState: ChangeRequestState;
+    actions?: ReactNode;
+}> = ({ change, currentReleasePlan, changeRequestState, actions }) => {
+    const releasePlan =
+        changeRequestState === 'Applied' && change.payload.snapshot
+            ? change.payload.snapshot
+            : currentReleasePlan;
+
+    if (!releasePlan) return;
+
+    return (
+        <>
+            <ChangeItemCreateEditDeleteWrapper>
+                <ChangeItemInfo>
+                    <Typography
+                        sx={(theme) => ({
+                            color: theme.palette.error.main,
+                        })}
+                    >
+                        - Deleting release plan:
+                    </Typography>
+                    <Typography>{releasePlan.name}</Typography>
+                </ChangeItemInfo>
+                <div>{actions}</div>
+            </ChangeItemCreateEditDeleteWrapper>
+            <ReleasePlan plan={releasePlan} readonly />
+        </>
+    );
+};
+
+const StartMilestone: FC<{
+    change: IChangeRequestStartMilestone;
+    currentReleasePlan?: IReleasePlan;
+    changeRequestState: ChangeRequestState;
+    actions?: ReactNode;
+}> = ({ change, currentReleasePlan, changeRequestState, actions }) => {
+    const releasePlan =
+        changeRequestState === 'Applied' && change.payload.snapshot
+            ? change.payload.snapshot
+            : currentReleasePlan;
+
+    if (!releasePlan) return;
+
+    const previousMilestone = releasePlan.milestones.find(
+        (milestone) => milestone.id === releasePlan.activeMilestoneId,
+    );
+
+    const newMilestone = releasePlan.milestones.find(
+        (milestone) => milestone.id === change.payload.milestoneId,
+    );
+
+    if (!newMilestone) return;
+
+    return (
+        <>
+            <ChangeItemCreateEditDeleteWrapper>
+                <ChangeItemInfo>
+                    <Typography color='success.dark'>
+                        + Start milestone:
+                    </Typography>
+                    <Typography>{newMilestone.name}</Typography>
+                    <TooltipLink
+                        tooltip={
+                            <StyledCodeSection>
+                                <EventDiff
+                                    entry={{
+                                        preData: previousMilestone,
+                                        data: newMilestone,
+                                    }}
+                                />
+                            </StyledCodeSection>
+                        }
+                        tooltipProps={{
+                            maxWidth: 500,
+                            maxHeight: 600,
+                        }}
+                    >
+                        <ViewDiff>View Diff</ViewDiff>
+                    </TooltipLink>
+                </ChangeItemInfo>
+                <div>{actions}</div>
+            </ChangeItemCreateEditDeleteWrapper>
+            <ReleasePlanMilestone readonly milestone={newMilestone} />
+        </>
+    );
+};
+
+const AddReleasePlan: FC<{
+    change: IChangeRequestAddReleasePlan;
+    currentReleasePlan?: IReleasePlan;
+    environmentName: string;
+    featureName: string;
+    actions?: ReactNode;
+}> = ({
+    change,
+    currentReleasePlan,
+    environmentName,
+    featureName,
+    actions,
+}) => {
+    const [currentTooltipOpen, setCurrentTooltipOpen] = useState(false);
+    const currentTooltipCloseTimeoutRef = useRef<NodeJS.Timeout>();
+    const openCurrentTooltip = () => {
+        if (currentTooltipCloseTimeoutRef.current) {
+            clearTimeout(currentTooltipCloseTimeoutRef.current);
+        }
+        setCurrentTooltipOpen(true);
+    };
+    const closeCurrentTooltip = () => {
+        currentTooltipCloseTimeoutRef.current = setTimeout(() => {
+            setCurrentTooltipOpen(false);
+        }, 100);
+    };
+
+    const planPreview = useReleasePlanPreview(
+        change.payload.templateId,
+        featureName,
+        environmentName,
+    );
+
+    const planPreviewDiff = {
+        ...planPreview,
+        discriminator: 'plan',
+        releasePlanTemplateId: change.payload.templateId,
+    };
+
+    return (
+        <>
+            <ChangeItemCreateEditDeleteWrapper>
+                <ChangeItemInfo>
+                    {currentReleasePlan ? (
+                        <Typography>
+                            Replacing{' '}
+                            <TooltipLink
+                                tooltip={
+                                    <div
+                                        onMouseEnter={() =>
+                                            openCurrentTooltip()
+                                        }
+                                        onMouseLeave={() =>
+                                            closeCurrentTooltip()
+                                        }
+                                    >
+                                        <ReleasePlan
+                                            plan={currentReleasePlan}
+                                            readonly
+                                        />
+                                    </div>
+                                }
+                                tooltipProps={{
+                                    open: currentTooltipOpen,
+                                    maxWidth: 500,
+                                    maxHeight: 600,
+                                }}
+                            >
+                                <span
+                                    onMouseEnter={() => openCurrentTooltip()}
+                                    onMouseLeave={() => closeCurrentTooltip()}
+                                >
+                                    current
+                                </span>
+                            </TooltipLink>{' '}
+                            release plan with:
+                        </Typography>
+                    ) : (
+                        <Typography color='success.dark'>
+                            + Adding release plan:
+                        </Typography>
+                    )}
+                    <Typography>{planPreview.name}</Typography>
+                    {currentReleasePlan && (
+                        <TooltipLink
+                            tooltip={
+                                <StyledCodeSection>
+                                    <EventDiff
+                                        entry={{
+                                            preData: currentReleasePlan,
+                                            data: planPreviewDiff,
+                                        }}
+                                    />
+                                </StyledCodeSection>
+                            }
+                            tooltipProps={{
+                                maxWidth: 500,
+                                maxHeight: 600,
+                            }}
+                        >
+                            <ViewDiff>View Diff</ViewDiff>
+                        </TooltipLink>
+                    )}
+                </ChangeItemInfo>
+                <div>{actions}</div>
+            </ChangeItemCreateEditDeleteWrapper>
+            <ReleasePlan plan={planPreview} readonly />
+        </>
+    );
+};
+
+/**
+ * Deprecated: use ReleasePlanChange instead. Remove file with flag crDiffView
+ * @deprecated
+ */
+export const LegacyReleasePlanChange: FC<{
+    actions?: ReactNode;
+    change:
+        | IChangeRequestAddReleasePlan
+        | IChangeRequestDeleteReleasePlan
+        | IChangeRequestStartMilestone;
+    environmentName: string;
+    featureName: string;
+    projectId: string;
+    changeRequestState: ChangeRequestState;
+}> = ({
+    actions,
+    change,
+    featureName,
+    environmentName,
+    projectId,
+    changeRequestState,
+}) => {
+    const { releasePlans } = useReleasePlans(
+        projectId,
+        featureName,
+        environmentName,
+    );
+    const currentReleasePlan = releasePlans[0];
+
+    return (
+        <>
+            {change.action === 'addReleasePlan' && (
+                <AddReleasePlan
+                    change={change}
+                    currentReleasePlan={currentReleasePlan}
+                    environmentName={environmentName}
+                    featureName={featureName}
+                    actions={actions}
+                />
+            )}
+            {change.action === 'deleteReleasePlan' && (
+                <DeleteReleasePlan
+                    change={change}
+                    currentReleasePlan={currentReleasePlan}
+                    changeRequestState={changeRequestState}
+                    actions={actions}
+                />
+            )}
+            {change.action === 'startMilestone' && (
+                <StartMilestone
+                    change={change}
+                    currentReleasePlan={currentReleasePlan}
+                    changeRequestState={changeRequestState}
+                    actions={actions}
+                />
+            )}
+        </>
+    );
+};

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

@@ -10,10 +10,11 @@ import type {
 import { useReleasePlanPreview } from 'hooks/useReleasePlanPreview';
 import { useReleasePlans } from 'hooks/api/getters/useReleasePlans/useReleasePlans';
 import { TooltipLink } from 'component/common/TooltipLink/TooltipLink';
-import EventDiff from 'component/events/EventDiff/EventDiff';
+import { EventDiff } from 'component/events/EventDiff/EventDiff';
 import { ReleasePlan } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlan';
 import { ReleasePlanMilestone } from 'component/feature/FeatureView/FeatureOverview/ReleasePlan/ReleasePlanMilestone/ReleasePlanMilestone';
 import type { IReleasePlan } from 'interfaces/releasePlans';
+import { Tab, TabList, TabPanel, Tabs } from './ChangeTabComponents.tsx';
 
 export const ChangeItemWrapper = styled(Box)({
     display: 'flex',
@@ -111,36 +112,34 @@ const StartMilestone: FC<{
     if (!newMilestone) return;
 
     return (
-        <>
+        <Tabs>
             <ChangeItemCreateEditDeleteWrapper>
                 <ChangeItemInfo>
                     <Typography color='success.dark'>
                         + Start milestone:
                     </Typography>
                     <Typography>{newMilestone.name}</Typography>
-                    <TooltipLink
-                        tooltip={
-                            <StyledCodeSection>
-                                <EventDiff
-                                    entry={{
-                                        preData: previousMilestone,
-                                        data: newMilestone,
-                                    }}
-                                />
-                            </StyledCodeSection>
-                        }
-                        tooltipProps={{
-                            maxWidth: 500,
-                            maxHeight: 600,
-                        }}
-                    >
-                        <ViewDiff>View Diff</ViewDiff>
-                    </TooltipLink>
                 </ChangeItemInfo>
-                <div>{actions}</div>
+                <div>
+                    <TabList>
+                        <Tab>Change</Tab>
+                        <Tab>View diff</Tab>
+                    </TabList>
+                    {actions}
+                </div>
             </ChangeItemCreateEditDeleteWrapper>
-            <ReleasePlanMilestone readonly milestone={newMilestone} />
-        </>
+            <TabPanel>
+                <ReleasePlanMilestone readonly milestone={newMilestone} />
+            </TabPanel>
+            <TabPanel>
+                <EventDiff
+                    entry={{
+                        preData: previousMilestone,
+                        data: newMilestone,
+                    }}
+                />
+            </TabPanel>
+        </Tabs>
     );
 };
 
@@ -183,75 +182,78 @@ const AddReleasePlan: FC<{
         releasePlanTemplateId: change.payload.templateId,
     };
 
-    return (
-        <>
-            <ChangeItemCreateEditDeleteWrapper>
-                <ChangeItemInfo>
-                    {currentReleasePlan ? (
-                        <Typography>
-                            Replacing{' '}
-                            <TooltipLink
-                                tooltip={
-                                    <div
-                                        onMouseEnter={() =>
-                                            openCurrentTooltip()
-                                        }
-                                        onMouseLeave={() =>
-                                            closeCurrentTooltip()
-                                        }
-                                    >
-                                        <ReleasePlan
-                                            plan={currentReleasePlan}
-                                            readonly
-                                        />
-                                    </div>
-                                }
-                                tooltipProps={{
-                                    open: currentTooltipOpen,
-                                    maxWidth: 500,
-                                    maxHeight: 600,
-                                }}
-                            >
-                                <span
-                                    onMouseEnter={() => openCurrentTooltip()}
-                                    onMouseLeave={() => closeCurrentTooltip()}
-                                >
-                                    current
-                                </span>
-                            </TooltipLink>{' '}
-                            release plan with:
-                        </Typography>
-                    ) : (
+    if (!currentReleasePlan) {
+        return (
+            <>
+                <ChangeItemCreateEditDeleteWrapper>
+                    <ChangeItemInfo>
                         <Typography color='success.dark'>
                             + Adding release plan:
                         </Typography>
-                    )}
-                    <Typography>{planPreview.name}</Typography>
-                    {currentReleasePlan && (
+                        <Typography>{planPreview.name}</Typography>
+                    </ChangeItemInfo>
+                    <div>{actions}</div>
+                </ChangeItemCreateEditDeleteWrapper>
+                <ReleasePlan plan={planPreview} readonly />
+            </>
+        );
+    }
+
+    return (
+        <Tabs>
+            <ChangeItemCreateEditDeleteWrapper>
+                <ChangeItemInfo>
+                    <Typography>
+                        Replacing{' '}
                         <TooltipLink
                             tooltip={
-                                <StyledCodeSection>
-                                    <EventDiff
-                                        entry={{
-                                            preData: currentReleasePlan,
-                                            data: planPreviewDiff,
-                                        }}
+                                <div
+                                    onMouseEnter={() => openCurrentTooltip()}
+                                    onMouseLeave={() => closeCurrentTooltip()}
+                                >
+                                    <ReleasePlan
+                                        plan={currentReleasePlan}
+                                        readonly
                                     />
-                                </StyledCodeSection>
+                                </div>
                             }
                             tooltipProps={{
+                                open: currentTooltipOpen,
                                 maxWidth: 500,
                                 maxHeight: 600,
                             }}
                         >
-                            <ViewDiff>View Diff</ViewDiff>
-                        </TooltipLink>
-                    )}
+                            <span
+                                onMouseEnter={() => openCurrentTooltip()}
+                                onMouseLeave={() => closeCurrentTooltip()}
+                            >
+                                current
+                            </span>
+                        </TooltipLink>{' '}
+                        release plan with:
+                    </Typography>
+                    <Typography>{planPreview.name}</Typography>
                 </ChangeItemInfo>
-                <div>{actions}</div>
+                <div>
+                    <TabList>
+                        <Tab>Changes</Tab>
+                        <Tab>View diff</Tab>
+                    </TabList>
+                    {actions}
+                </div>
             </ChangeItemCreateEditDeleteWrapper>
-            <ReleasePlan plan={planPreview} readonly />
-        </>
+            <TabPanel>
+                <ReleasePlan plan={planPreview} readonly />
+            </TabPanel>
+            <TabPanel>
+                <EventDiff
+                    entry={{
+                        preData: currentReleasePlan,
+                        data: planPreviewDiff,
+                    }}
+                />
+            </TabPanel>
+        </Tabs>
     );
 };