Add more tests to expand coverage

[panda-sandeep]

Check the current tests and identify all areas that need e2e coverage.

[Spyyy004]

Test Coverage Gap Analysis : RICE Ranking

I audited the full codebase against the existing 8 test files (118 tests, all passing). Identified 13 distinct coverage gaps and scored each using the RICE framework (Reach × Impact × Confidence ÷ Effort).

Scoring Criteria

Factor	Scale	Description
Reach	1–10	How many downstream features/code paths depend on this module
Impact	0.5–3	Severity if a bug goes undetected (0.5 = minimal, 3 = massive)
Confidence	50–100%	How confident we are that tests here would catch real regressions
Effort	1–6 person-days	Estimated effort to write comprehensive tests

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Top 3

🥇 executeWithAutoHealing : RICE: 9.0

R	I	C	E	Score
5	2	90%	1	9.0

• Zero tests for this exported public API
• Simple AI vs cached branching + aiFlowTimeout, only ~20 lines but controls whether users run cached Playwright flows or AI-powered fallbacks
• High confidence: deterministic branching on process.env.AI and test.info().retry
• Very low effort to test (mock two async functions, assert which one gets called)

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🥈 createTabManager (NEW module) : RICE: 8.4

R	I	C	E	Score
7	2	90%	1.5	8.4

• Brand-new module (src/utils/tab-manager.ts) with zero tests
• Now used in every runSteps execution, manages active tab, auto-switches on context.on("page"), handles tab close cleanup
• Pure logic (no AI mocking needed), high confidence in test value
• Key paths: switchTo("main" | "latest" | index), invalid target error, close event index adjustment

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🥉 resolveModel (models.ts) — RICE: 8.0

R	I	C	E	Score
10	3	80%	3	8.0

• Zero tests : every AI call in the entire framework routes through this function
• Now has 4 gateway branches (none → direct, vercel, openrouter, cloudflare) after latest pull added Cloudflare AI Gateway support
• 6 ConfigurationError throws for missing API keys, model alias resolution maps, unknown provider AIModelError
• A bug here silently routes to the wrong model or crashes on misconfiguration — maximum blast radius

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Full Ranking (for reference)

Rank	Module	R	I	C	E	RICE
1	executeWithAutoHealing	5	2	90%	1	9.0
2	createTabManager	7	2	90%	1.5	8.4
3	resolveModel	10	3	80%	3	8.0
4	runUserFlow	8	3	80%	3	6.4
5	Custom error hierarchy	6	0.5	100%	0.5	6.0
6	data-cache.ts (9 untested fns)	8	2	80%	3	4.3
7	utils/index.ts (6 untested fns)	9	2	70%	3	4.2
8	extractDataWithAI	4	1	80%	1	3.2
9	Prompt builders	8	0.5	80%	1	3.2
10	runSteps untested branches	10	2	70%	5	2.8
11	extractEmailContent	3	2	80%	2	2.4
12	tools.ts (18 tools)	8	1	70%	6	0.9
13	emailsinkProvider	2	1	70%	1.5	0.9

Let me know what are your thoughts? @panda-sandeep
If you agree, I can raise a PR by adding test cases for the top 3 features.