Alerting: Prevent incorrect prefill params to crash the rule editor (#106395)

also introduces "zod" as dependency

package.json

@@ -259,7 +259,8 @@
     "webpack-subresource-integrity": "^5.2.0-rc.1",
     "webpackbar": "^7.0.0",
     "yaml": "^2.0.0",
-    "yargs": "^17.5.1"
+    "yargs": "^17.5.1",
+    "zod": "^3.25.55"
   },
   "dependencies": {
     "@bsull/augurs": "^0.10.0",

public/app/features/alerting/unified/components/rule-editor/alert-rule-form/AlertRuleForm.tsx

@@ -106,9 +106,7 @@ export const AlertRuleForm = ({ existing, prefill, isManualRestore }: Props) =>
       return formValuesFromPrefill(prefill);
     }
 
-    const defaultRuleType = ruleType || RuleFormType.grafana;
-
-    return defaultFormValuesForRuleType(defaultRuleType);
+    return defaultFormValuesForRuleType(ruleType);
   }, [existing, prefill, ruleType]);
 
   const formAPI = useForm<RuleFormValues>({

public/app/features/alerting/unified/rule-editor/formDefaults.ts

@@ -1,4 +1,5 @@
 import { clamp } from 'lodash';
+import { z } from 'zod/v4';
 
 import { config } from '@grafana/runtime';
 import { RuleWithLocation } from 'app/types/unified-alerting';
@@ -136,9 +137,12 @@ export function formValuesFromQueryParams(ruleDefinition: string, type: RuleForm
 }
 
 export function formValuesFromPrefill(rule: Partial<RuleFormValues>): RuleFormValues {
+  // coerce prefill params to a valid RuleFormValues interface
+  const parsedRule = ruleFormValuesSchema.parse(rule);
+
   return revealHiddenQueries({
     ...getDefaultFormValues(rule.type),
-    ...rule,
+    ...parsedRule,
   });
 }
 
@@ -169,3 +173,82 @@ export function translateRouteParamToRuleType(param = ''): RuleFormType {
 
   return RuleFormType.grafana;
 }
+
+// we use this schema to coerce prefilled query params into a valid "FormValues" interface
+const ruleFormValuesSchema = z.looseObject({
+  name: z.string().optional(),
+  type: z.enum(RuleFormType).catch(RuleFormType.grafana),
+  dataSourceName: z.string().optional().default(''),
+  group: z.string().optional(),
+  labels: z
+    .array(
+      z.object({
+        key: z.string(),
+        value: z.string(),
+      })
+    )
+    .optional()
+    .default([]),
+  annotations: z
+    .array(
+      z.object({
+        key: z.string(),
+        value: z.string(),
+      })
+    )
+    .optional()
+    .default([]),
+  queries: z.array(z.any()).optional(),
+  condition: z.string().optional(),
+  noDataState: z
+    .enum(GrafanaAlertStateDecision)
+    .optional()
+    .default(GrafanaAlertStateDecision.NoData)
+    .catch(GrafanaAlertStateDecision.NoData),
+  execErrState: z
+    .enum(GrafanaAlertStateDecision)
+    .optional()
+    .default(GrafanaAlertStateDecision.Error)
+    .catch(GrafanaAlertStateDecision.Error),
+  folder: z
+    .union([
+      z.object({
+        title: z.string(),
+        uid: z.string(),
+      }),
+      z.undefined(),
+    ])
+    .optional(),
+  evaluateEvery: z.string().optional(),
+  evaluateFor: z.string().optional().default('0s'),
+  keepFiringFor: z.string().optional(),
+  isPaused: z.boolean().optional().default(false),
+  manualRouting: z.boolean().optional(),
+  contactPoints: z
+    .record(
+      z.string(),
+      z.object({
+        selectedContactPoint: z.string(),
+        overrideGrouping: z.boolean(),
+        groupBy: z.array(z.string()),
+        overrideTimings: z.boolean(),
+        groupWaitValue: z.string(),
+        groupIntervalValue: z.string(),
+        repeatIntervalValue: z.string(),
+        muteTimeIntervals: z.array(z.string()),
+        activeTimeIntervals: z.array(z.string()),
+      })
+    )
+    .optional(),
+  editorSettings: z
+    .object({
+      simplifiedQueryEditor: z.boolean(),
+      simplifiedNotificationEditor: z.boolean(),
+    })
+    .optional(),
+  metric: z.string().optional(),
+  targetDatasourceUid: z.string().optional(),
+  namespace: z.string().optional(),
+  expression: z.string().optional(),
+  missingSeriesEvalsToResolve: z.number().optional(),
+});

yarn.lock

@@ -18450,6 +18450,7 @@ __metadata:
     whatwg-fetch: "npm:3.6.20"
     yaml: "npm:^2.0.0"
     yargs: "npm:^17.5.1"
+    zod: "npm:^3.25.55"
   dependenciesMeta:
     prettier@3.4.2:
       unplugged: true
@@ -32978,3 +32979,10 @@ __metadata:
   checksum: 10/0e35432dcca7f053e63f5dd491a87c78abe0d981817547252c3b6d05f0f58788695d1a69724759c6501dff3fd62929be24c9f314a3625179bee889150f7a61fa
   languageName: node
   linkType: hard
+
+"zod@npm:^3.25.55":
+  version: 3.25.55
+  resolution: "zod@npm:3.25.55"
+  checksum: 10/1f86d370730fc1eed10fe584079bfebd0008303722f2da21057d493e784b42f0b1edbac028b5a788e2e04bd31da070eac8e8d5f237ec968bc2a6aa30985fa9d6
+  languageName: node
+  linkType: hard