Enforce Fail-Fast Validation for Network Configurations in Subgraph Templating

[magqqgq]

Description

This pull request resolves Medium severity reliability and configuration findings identified in polymarket-subgraph during the workspace audit. Previously, missing or unrecognised network targets defaulted to empty evaluation contexts (networks[undefined]), prompting Handlebars to silently compile syntactically valid manifests with blank contract addresses and missing startBlock fields. Additionally, templatify.ts only accepted positional arguments, breaking scripts relying on NETWORK_NAME. This PR adds dual input support (argv and env) and fail-fast assertions against networks.yaml definitions.

Key Changes & Remediations

Configuration Resolution & Fail-Fast Guards (templatify.ts)

• Dual Target Resolution: Updated network resolution to check process.argv[2] || process.env.NETWORK_NAME, ensuring alignment with prepare:* package scripts that pass network targets via environment variables.
• Missing Target Assertion: Enforced an explicit error when no network name is supplied, eliminating confusing error messages that referenced obsolete flags.
• Target Existence Assertion: Added an explicit check ensuring networks[networkName] exists before compiling templates. If an invalid network is supplied, the script throws an actionable error enumerating valid entries defined in networks.yaml rather than generating empty manifests that fail silently at deployment.

How to Review

1. Target Loading: Verify in templatify.ts that networkName correctly evaluates positional arguments and process.env.NETWORK_NAME.
2. Fail-Fast Guard: Test invoking templatify.ts with no arguments and with an unknown target (e.g., ts-node ./templatify.ts invalid-net) to ensure execution halts with clear error diagnostics.
3. Template Compilation: Confirm valid network generation (e.g., matic) populates addresses and configurations as expected.

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Note

Low Risk
Build-time subgraph templating only; no runtime auth, payments, or production indexing logic changes.

Overview
templatify.ts now resolves the target network from the first CLI argument or NETWORK_NAME, fixing prepare:mainnet / prepare:matic / prepare:mumbai scripts that only set the env var.

Validation runs before template compilation: missing network names get a corrected error (no obsolete SUBGRAPH hint), and unknown keys fail fast with a list of valid entries from networks.yaml instead of emitting subgraph manifests with blank addresses and empty startBlock values.

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