Java Heap Optimizer Skill — Agent E2E Test Plan

Prerequisites

Read SKILL.md first to understand instructions, heuristics, SQL queries, and expected outputs.

Ensure you have access to:

  1. A Perfetto-formatted Java heap dump file (e.g., ~/traces/app-heap.pb or a downloadable URL).
  2. The local source code workspace corresponding to the heap dump's target package.

Test 1: Tool Available & Download Setup

Prompt: “Set up trace processor and prepare to analyze a heap dump.”

Verify:

  • Agent downloads or locates the trace_processor binary using:
    curl -LO https://get.perfetto.dev/trace_processor
chmod +x trace_processor
  • Agent confirms trace_processor is installed and executable.

Test 2: Analyze Heap Dump - Location Request

Prompt: “Can you analyze a heap dump and find caching optimizations for our app?”

Verify:

  • Agent asks the user for the location of the heap dump (URL or local path).
  • Agent asks the user for a specific package name they are interested in optimizing.

Test 3: Remote Download & High-Level Analysis

Setup: Have a Perfetto Java heap dump URL ready (e.g., https://ui.perfetto.dev/#!/?s=0d259d2b6ef1e5e5970b83c47b5e531aff2d0fd9).

Prompt: “Analyze the heap dump at https://ui.perfetto.dev/#!/?s=0d259d2b6ef1e5e5970b83c47b5e531aff2d0fd9 to find caching opportunities. Focus on package ‘com.example.sampleapp’.”

Verify:

  • Agent downloads the heap dump file from the URL.
  • Agent executes query_most_repeated_objects.sql and query_size_frequencies.sql using trace_processor.
  • Agent filters out primitives and java.lang.* classes.
  • Agent prioritizes classes matching com.example.sampleapp.
  • Agent lists potential caching candidates in the prompt, categorized by heuristics:
    • High cumulative size objects that are not very often repeated.
    • Objects that repeat often independent of cumulative size.
    • Stateless objects.

Test 4: Verify Duplicate References via SQL

Setup: Identify candidate classes from Test 3 (e.g., Owner: MediaItem, Owned: MediaMetadata).

Prompt: “I suspect that MediaMetadata objects are duplicated and owned by MediaItem. Can you verify if MediaItem owns MediaMetadata in the heap dump ‘/home/user/traces/app-heap.pb’?”

Verify:

  • Agent executes query_heap_references.sql using trace_processor.
  • Agent replaces <owner_classname> with MediaItem and <owned_classname> with MediaMetadata.
  • Agent interprets the results to confirm or refute the ownership relationship and reports back with details.

Test 5: Deep Code Analysis

Setup: Locate a target class file (e.g., MediaMetadata.java) and its referencing parent classes in the workspace.

Prompt: “We found a candidate class com.google.android.apps.photos.MediaMetadata which is repeated 15,000 times. The source code is in the workspace under src/com/google/android/apps/photos/MediaMetadata.java. Perform a deep analysis and present the findings.”

Verify:

  • Agent searches for and reads MediaMetadata.java and its parent referencing files in the workspace.
  • Agent analyzes how the instances are constructed, stored, and whether they are stateless or mutable.
  • Agent creates a markdown report listing:
    • Why MediaMetadata is a good candidate.
    • Implementation design details (e.g., static deduplication, LruCache).
    • Expected memory savings and file path to the results.

Test 6: Generate Implementation Plan

Prompt: “Create a detailed implementation plan for caching MediaMetadata in MediaItem. Include expected savings.”

Verify:

  • Agent creates or updates analysis.md or implementation_plan.md.
  • Agent provides a detailed estimate of memory savings (detailing upper and lower bounds if an exact estimate isn't possible).
  • Agent describes any architectural trade-offs that impact estimated savings.

Test 7: Apply Caching Optimization (Local Only)

Prompt: “I have reviewed the implementation plan. Please apply the caching changes to MediaMetadata.java and its references.”

Verify:

  • Agent implements the implementation plan provided.
  • Agent preserves unrelated code structures, comments, and docstrings.
  • Agent asks the user to review the local diffs.