feat(preprod): Add size monitor UI by chromy · Pull Request #108211 · getsentry/sentry

chromy · 2026-02-13T11:37:58Z

Add list, detail, and create/edit views for the preprod_size_analysis
detector type ("Mobile Builds"). Users can configure a metric
(install/download size), measurement (absolute/diff/relative), optional
build filters, and priority thresholds. Includes a live preview section,
detector type selection form, and routes at /detectors/mobile-builds/.

PRs:

feat(preprod): Add Size Analysis detector #108208 Add size_analysis detector
feat(preprod): Hook size analysis detector to diff #108209 Hook size analysis detector to diff
feat(preprod): Add new issue type to frontend #108210 Add new issue type to frontend
feat(preprod): Add size monitor UI #108211 Add size monitor UI (this PR)

Design doc

github-actions · 2026-02-13T11:38:14Z

🚨 Warning: This pull request contains Frontend and Backend changes!

It's discouraged to make changes to Sentry's Frontend and Backend in a single pull request. The Frontend and Backend are not atomically deployed. If the changes are interdependent of each other, they must be separated into two pull requests and be made forward or backwards compatible, such that the Backend or Frontend can be safely deployed independently.

Have questions? Please ask in the #discuss-dev-infra channel.

static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx

src/sentry/preprod/size_analysis/grouptype.py

cursor

Cursor Bugbot has reviewed your changes and found 6 potential issues.

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cursor · 2026-02-13T11:44:17Z

src/sentry/preprod/size_analysis/grouptype.py

+            priority=DetectorPriorityLevel.HIGH,
+            occurrence=occurrence,
+            event_data=event_data,
+        )


Detector ignores configured thresholds

High Severity

PreprodSizeAnalysisDetectorHandler.evaluate_impl always creates a HIGH IssueOccurrence and never evaluates detector.conditionGroup, metric, or measurement. This makes preprod_size_analysis monitors fire on every packet, regardless of configured thresholds.

cursor · 2026-02-13T11:44:17Z

static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx

+      measurement: data.measurement,
+    },
+    dataSources: [{}],
+  };


Filter settings never reach backend

Medium Severity

The form captures filters, but preprodFormDataToEndpointPayload always sends dataSources: [{}], so filter values are dropped. On the backend, SizeAnalysisDataSourceValidator declares no fields and creates SizeAnalysisSubscription with only project, so configured filters are never persisted or applied.

Additional Locations (1)

src/sentry/preprod/size_analysis/grouptype.py#L157-L167

cursor · 2026-02-13T11:44:17Z

static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx

+
+  const highThreshold = String(bytesToMb(String(highCondition?.comparison ?? '')));
+  const mediumThreshold = String(bytesToMb(String(mediumCondition?.comparison ?? '')));
+  const lowThreshold = String(bytesToMb(String(lowCondition?.comparison ?? '')));


Relative thresholds get converted as bytes

Medium Severity

preprodSavedDetectorToFormData always runs comparison values through bytesToMb, including relative_diff detectors where thresholds are percentages. Editing and saving these detectors rewrites percentage thresholds to tiny MB-converted values, corrupting monitor configuration.

cursor · 2026-02-13T11:44:17Z

static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx

+
+  const highThreshold = String(bytesToMb(String(highCondition?.comparison ?? '')));
+  const mediumThreshold = String(bytesToMb(String(mediumCondition?.comparison ?? '')));
+  const lowThreshold = String(bytesToMb(String(lowCondition?.comparison ?? '')));


Missing thresholds become zero on edit

High Severity

preprodSavedDetectorToFormData converts absent threshold conditions into "0" by passing empty values through bytesToMb. Because "0" is truthy, createPreprodConditions later persists LOW/MEDIUM thresholds at zero, changing monitor behavior after a simple edit.

cursor · 2026-02-13T11:44:17Z

static/app/views/detectors/components/detectorTypeForm.tsx

  'metric_issue',
  'monitor_check_in_failure',
  'uptime_domain_failure',
+  'preprod_size_analysis',


Feature gate can be bypassed via query

Medium Severity

preprod_size_analysis is always accepted by detectorType query parsing, while UI gating only hides the option. A user can still set ?detectorType=preprod_size_analysis and reach NewPreprodDetectorForm even without the preprod-size-monitors-frontend feature.

Additional Locations (1)

static/app/views/detectors/components/forms/index.tsx#L52-L55

cursor · 2026-02-13T11:44:17Z

src/sentry/preprod/size_analysis/grouptype.py

+    def validate_data_sources(self, value: list[Any]) -> list[Any]:
+        if not value:
+            raise serializers.ValidationError("At least one data source is required")
+        return value


Missing data source validation on create

Medium Severity

data_sources is marked required=False, so requests that omit dataSources skip validate_data_sources. This allows creating preprod_size_analysis detectors without any SizeAnalysisSubscription, leaving monitors that never receive packets and silently never trigger.

sentry · 2026-02-13T11:45:38Z

static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx

+function mbToBytes(mb: string): number {
+  const value = parseFloat(mb);
+  if (Number.isNaN(value)) {
+    return 0;
+  }
+  return value * 1024 * 1024;
+}


Bug: The detector details page displays the raw byte value of a threshold with an "MB" unit, leading to a nonsensical value like "10485760 MB" instead of "10 MB".
_{Severity: MEDIUM}

Suggested Fix

The display component in detect.tsx should convert the raw byte value from condition.comparison back to megabytes before rendering it. This will ensure the value shown in the UI is consistent with the user's original input.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not valid. Location: static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx#L60-L66 Potential issue: The new form in `mobileBuildFormData.tsx` converts a user-entered value in megabytes (MB) to bytes using a binary factor (1024*1024). For example, an input of "10 MB" is stored as `10485760` bytes. However, the detector details page in `detect.tsx` later displays this raw byte value directly from `condition.comparison` while incorrectly appending the "MB" unit. This results in a confusing and incorrect UI where a threshold set as "10 MB" is displayed as "10485760 MB".

github-actions · 2026-02-13T11:47:40Z

This PR has a migration; here is the generated SQL for src/sentry/preprod/migrations/0027_size_analysis_subscription.py

for 0027_size_analysis_subscription in preprod

--
-- Create model SizeAnalysisSubscription
--
CREATE TABLE "sentry_sizeanalysissubscription" ("id" bigint NOT NULL PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY, "date_updated" timestamp with time zone NOT NULL, "date_added" timestamp with time zone NOT NULL, "project_id" bigint NOT NULL);
ALTER TABLE "sentry_sizeanalysissubscription" ADD CONSTRAINT "sentry_sizeanalysiss_project_id_41e3355e_fk_sentry_pr" FOREIGN KEY ("project_id") REFERENCES "sentry_project" ("id") DEFERRABLE INITIALLY DEFERRED NOT VALID;
ALTER TABLE "sentry_sizeanalysissubscription" VALIDATE CONSTRAINT "sentry_sizeanalysiss_project_id_41e3355e_fk_sentry_pr";
CREATE INDEX CONCURRENTLY "sentry_sizeanalysissubscription_project_id_41e3355e" ON "sentry_sizeanalysissubscription" ("project_id");

chromy requested review from a team as code owners February 13, 2026 11:37

github-actions bot added Scope: Frontend Automatically applied to PRs that change frontend components Scope: Backend Automatically applied to PRs that change backend components labels Feb 13, 2026

sentry bot reviewed Feb 13, 2026

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static/app/views/detectors/components/forms/mobileBuild/mobileBuildFormData.tsx Outdated Show resolved Hide resolved

src/sentry/preprod/size_analysis/grouptype.py Outdated Show resolved Hide resolved

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chromy marked this pull request as draft February 13, 2026 11:45

chromy changed the base branch from master to chromy/2026-03-12-add-issue-type-to-frontend February 13, 2026 11:46

This was referenced Feb 13, 2026

feat(preprod): Add SizeAnalysisSubscription as a DataSource #108172

Draft

feat(preprod): Add Size Analysis detector #108208

Open

feat(preprod): Hook size analysis detector to diff #108209

Draft

feat(preprod): Add new issue type to frontend #108210

Draft

chromy force-pushed the chromy/2026-03-12-add-issue-type-to-frontend branch 2 times, most recently from faf4368 to 3f32d87 Compare February 16, 2026 18:36

feat(preprod): Add size monitor UI

3117ac8

chromy force-pushed the chromy/2026-03-12-add-size-monitor-to-frontend branch from 759cbb5 to 3117ac8 Compare February 16, 2026 18:36

vercel bot deployed to Preview February 16, 2026 18:39 View deployment

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chromy commented Feb 13, 2026 •

edited

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chromy commented Feb 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Detector ignores configured thresholds

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Filter settings never reach backend

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Relative thresholds get converted as bytes

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Missing thresholds become zero on edit

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Feature gate can be bypassed via query

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Missing data source validation on create

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chromy commented Feb 13, 2026 •

edited

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