docs: schema files are the prerequisite for column-level tests + how to generate

[wjduenow]

Summary

Documents a non-obvious prerequisite surfaced while estimating a full-repo generate run: SignalForge drafts column-level tests from model.columns, which dbt populates from schema .yml files. A model with no schema yml has zero columns in the manifest, so the drafter can only produce model-level variants (row_count_*) — not not_null / unique / accepted_values / per-column custom_sql.

Motivation: in a real project, 103 of 104 models had no schema ymls → near-zero column-level coverage, which isn't obvious from the CLI output.

Changes

• docs/manifest-loader-ops.md — new section "Column metadata: schema files are the prerequisite for column-level tests" (placed just before the existing catalog.json types section): explains the manifest-is-source-of-truth model, the zero-column consequence (incl. the ingest anchor-check that drops tests referencing undeclared columns), a one-liner to check a model's column count, how to generate schema files (dbt-codegen generate_model_yaml or by hand), and that dbt docs generate enriches types but is not a substitute for schema files (it never adds a column the manifest lacks).
• docs/draft-ops.md — a short prerequisite callout in the Overview linking to the new section.

Testing

• mkdocs build (CI-equivalent, non-strict) passes; the new cross-reference anchor resolves (verified it is not among the pre-existing strict-mode link warnings).

Separate from #202 (kept off that in-review PR since it's an independent docs improvement).

🤖 Generated with Claude Code

Summary by CodeRabbit

Release Notes

• Documentation
  • Added prerequisite notes explaining that column-level tests require dbt schema YAML files. Models without schemas will only generate model-level test variants.
  • Included guidance for generating schema files using dbt-codegen or manual YAML, with clarification on schema metadata requirements.

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📥 Commits

Reviewing files that changed from the base of the PR and between 365a89d and e4a5bbc.

📒 Files selected for processing (2)

• docs/draft-ops.md
• docs/manifest-loader-ops.md

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📝 Walkthrough

Walkthrough

This PR adds prerequisite documentation across two guides explaining that dbt schema YAML files are required to populate model.columns in manifest.json, which enables SignalForge to draft column-level tests. Models without schema files produce zero column anchors, restricting output to model-level variants only.

Changes

Schema YAML Prerequisites for Column-Level Tests

Layer / File(s)

Summary

Schema YAML prerequisite documentation docs/draft-ops.md, docs/manifest-loader-ops.md

Added explicit prerequisite notes explaining that column-level tests require dbt schema YAML to populate model.columns in manifest.json. draft-ops.md notes that models without schema yield zero columns, restricting output to model-level variants. manifest-loader-ops.md adds a new "Column metadata" section with concrete guidance on generating schema files via dbt-codegen or manual YAML authoring, and clarifies that catalog.json provides column types only for already-declared columns.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Possibly related PRs

• wjduenow/SignalForge#161: Addresses manifest loading of column metadata and types (merging catalog.json into Column.data_type), directly complementing this PR's documentation of schema YAML prerequisites for column-level test generation.

Poem

🐰 A schema declares what columns contain,
So tests can be drafted, again and again!
No YAML, no anchors—just models stay true,
But docs make it clear: here's what drafters will do! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely summarizes the main changes: documentation clarification that schema files are a prerequisite for column-level tests and instructions on how to generate them.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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