enable float threshold for chart alert (#773)

- add new schema to support float threshold for chart alert
<img width="882" alt="image" src="https://github.com/user-attachments/assets/dd563bf2-9ae9-4c8f-ad63-731d8815518a" />

Tested alert:
<img width="1256" alt="image" src="https://github.com/user-attachments/assets/92683d01-ada4-48e7-bd2b-567aba949e4b" />



Ref: hdx-1640

Author: LYHuang

packages/app/src/components/DBEditTimeChartForm.tsx

@@ -12,7 +12,7 @@ import z from 'zod';
 import { zodResolver } from '@hookform/resolvers/zod';
 import { tcFromSource } from '@hyperdx/common-utils/dist/metadata';
 import {
-  AlertBaseSchema,
+  ChartAlertBaseSchema,
   ChartConfigWithDateRange,
   DateRange,
   DisplayType,
@@ -80,6 +80,8 @@ const isQueryReady = (queriedConfig: ChartConfigWithDateRange | undefined) =>
   (queriedConfig?.from?.tableName || queriedConfig?.metricTables) &&
   queriedConfig?.timestampValueExpression;
 
+const MINIMUM_THRESHOLD_VALUE = 0.0000000001; // to make alert input > 0
+
 const NumberFormatInputControlled = ({
   control,
   onSubmit,
@@ -293,7 +295,7 @@ const defaultTimeRange = parseTimeQuery('Past 1h', false) as [Date, Date];
 const zSavedChartConfig = z
   .object({
     // TODO: Chart
-    alert: AlertBaseSchema.optional(),
+    alert: ChartAlertBaseSchema.optional(),
   })
   .passthrough();
 
@@ -738,7 +740,7 @@ export default function EditTimeChartForm({
                   control={control}
                 />
                 <NumberInput
-                  min={1}
+                  min={MINIMUM_THRESHOLD_VALUE}
                   size="xs"
                   w={80}
                   control={control}

packages/app/src/utils/alerts.ts

@@ -13,6 +13,7 @@ import {
   AlertInterval,
   AlertSource,
   AlertThresholdType,
+  ChartAlertBaseSchema,
 } from '@hyperdx/common-utils/dist/types';
 
 import { Granularity } from '@/ChartUtils';
@@ -111,7 +112,7 @@ export const ALERT_CHANNEL_OPTIONS: Record<AlertChannelType, string> = {
   webhook: 'Webhook',
 };
 
-export const DEFAULT_TILE_ALERT: z.infer<typeof AlertBaseSchema> = {
+export const DEFAULT_TILE_ALERT: z.infer<typeof ChartAlertBaseSchema> = {
   threshold: 1,
   thresholdType: AlertThresholdType.ABOVE,
   interval: '5m',

packages/common-utils/src/types.ts

@@ -268,9 +268,14 @@ export const AlertBaseSchema = z.object({
     .optional(),
 });
 
-export const AlertSchema = AlertBaseSchema.and(
-  zSavedSearchAlert.or(zTileAlert),
-);
+export const ChartAlertBaseSchema = AlertBaseSchema.extend({
+  threshold: z.number().positive(),
+});
+
+export const AlertSchema = z.union([
+  z.intersection(AlertBaseSchema, zSavedSearchAlert),
+  z.intersection(ChartAlertBaseSchema, zTileAlert),
+]);
 
 export type Alert = z.infer<typeof AlertSchema>;
 
@@ -410,7 +415,10 @@ export const SavedChartConfigSchema = z.intersection(
     z.object({
       name: z.string(),
       source: z.string(),
-      alert: AlertBaseSchema.optional(),
+      alert: z.union([
+        AlertBaseSchema.optional(),
+        ChartAlertBaseSchema.optional(),
+      ]),
     }),
     _ChartConfigSchema.omit({
       connection: true,