Optimize property mapping and array operations for better performance

[Copilot]

Identified and fixed performance bottlenecks in property mapping and error collection logic.

Changes

Property mapping optimization (src/domain/mapping.ts)

• Reduced property access operations by 50% using loop-based mapping with single access per property
• Eliminated array allocations in buildHistoryProps() by building name parts array directly

Before:

if (wb["AI Summary"] !== undefined) props["AI Summary"] = wb["AI Summary"];
if (wb["Health 0-100"] !== undefined) props["Health 0-100"] = wb["Health 0-100"];
// ... 6 more properties

After:

const mappings = [["AI Summary", "AI Summary"], ["Health 0-100", "Health 0-100"], ...] as const;
for (const [key, propName] of mappings) {
  const value = wb[key];
  if (value !== undefined) props[propName] = value;
}

Error collection optimization (src/routes/analyze.ts)

• Replaced filter().map() chain with single-pass iteration
• Eliminated intermediate array allocation, reducing complexity from O(2n) to O(n)

Before:

errors: results.filter((r) => r.status === "error").map((r) => r.error || "error")

After:

const errors: string[] = [];
for (const result of results) {
  if (result.status === "error") errors.push(result.error || "error");
}

Removed unnecessary type conversion in HMAC verification path (Buffer.from(String(sig)) → Buffer.from(sig))

Test coverage

Added 8 unit tests covering property mapping edge cases (partial writebacks, empty objects, name building variations).

Original prompt

Identify and suggest improvements to slow or inefficient code

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[stevenschling13]

@copilot find solution to the error and assure this is ready for deployment

[Copilot]

Pull Request Overview

This PR introduces test coverage for the mapping functions and applies several performance optimizations and code quality improvements across the codebase. The changes focus on reducing redundant property access, improving type safety, and streamlining error collection logic.

Key changes:

• Adds comprehensive test suite for mapWritebacksToPhotos and buildHistoryProps functions
• Refactors mapping functions to use loop-based property mapping instead of repetitive if statements
• Optimizes error collection in analyze route to use a single iteration
• Removes unnecessary String() wrapper and improves type safety with as const assertions
• Updates pnpm lockfile with proper version 9 format

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 3 comments.

File	Description
test/mapping.test.ts	Adds new comprehensive test suite covering all mapping function behaviors including edge cases
src/routes/analyze.ts	Optimizes error collection logic and improves type safety with const assertions; removes redundant String() wrapper
src/domain/mapping.ts	Refactors property mapping to use loop-based approach for better maintainability and performance
pnpm-lock.yaml	Updates lockfile from version 5.4 to 9.0 format with complete dependency resolution

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

[Copilot]

The mappings array contains redundant tuples where the source and target property names are identical. Consider simplifying this to just an array of property names to reduce duplication and improve maintainability. You could map these to themselves in the loop: const simpleProps = ['AI Summary', 'Health 0-100', ...] as const; for (const key of simpleProps) { ... }

[Copilot]

Similar to the mappings in mapWritebacksToPhotos, this array contains redundant tuples. The same simplification applies here - use a single array of property names to reduce code duplication.

Suggested change

	const wbMappings = [
	["AI Summary", "AI Summary"],
	["Health 0-100", "Health 0-100"],
	["DLI mol", "DLI mol"],
	["VPD kPa", "VPD kPa"],
	["VPD OK", "VPD OK"],
	["DLI OK", "DLI OK"],
	["CO2 OK", "CO2 OK"],
	["Sev", "Sev"],
	] as const;
	for (const [key, propName] of wbMappings) {
	const value = input.wb[key];
	const wbProperties = [
	"AI Summary",
	"Health 0-100",
	"DLI mol",
	"VPD kPa",
	"VPD OK",
	"DLI OK",
	"CO2 OK",
	"Sev",
	] as const;
	for (const propName of wbProperties) {
	const value = input.wb[propName];

[Copilot]

[nitpick] While the comment states this collects errors 'efficiently', using filter and map would be more idiomatic and expressive: const errors = results.filter(r => r.status === 'error').map(r => r.error || 'error');. This achieves the same result with clearer intent, though it does iterate twice internally.

Suggested change

	// Collect errors efficiently during a single iteration
	const errors: string[] = [];
	for (const result of results) {
	if (result.status === "error") {
	errors.push(result.error || "error");
	}
	}
	// Collect errors using idiomatic filter/map
	const errors = results
	.filter(r => r.status === "error")
	.map(r => r.error || "error");

[Copilot]

@copilot find solution to the error and assure this is ready for deployment

The issue was missing node_modules - dependencies weren't installed. After running pnpm install, all checks pass:

✅ Build successful (TypeScript compilation)
✅ All 12 tests passing
✅ Linting passed (ESLint)
✅ Type checking passed
✅ CodeQL security scan: 0 vulnerabilities
✅ dist/ folder generated correctly

Deployment Ready - The code is ready for production deployment.

⚠️ Important: Ensure the HMAC_SECRET environment variable is set in your production environment for webhook security.