[jsteinich]

Closes #480.

#393 made generated provider and resource docs links follow the project's declared targetVersions. Module links were missed and stayed hardcoded, so an OpenTofu-only project got Terraform Registry links and prose reading "Docs at Terraform Registry".

Changes

• ModuleGenerator had no targetVersions at all — threaded through from ConstructsMaker.
• moduleDocsUrl() added to the Registry abstraction, beside the existing provider docsUrl().

	Terraform	OpenTofu
module	/modules/{ns}/{name}/{tgt}/{ver}	/module/{ns}/{name}/{tgt}/**v**{ver}
submodule	.../{ver}/submodules/{sub}	.../v{ver}/submodule/{sub} (singular)

How the OpenTofu shapes were established

From getDocumentationUrl.ts and router.tsx in opentofu/registry-ui — the same source as the provider paths in #393:

case "module":
  return `/module/${vars.namespace}/${vars.name}/${vars.target_system}/${vars.version || "latest"}`;

Then confirmed against rendered pages, which matters here: search.opentofu.org does not 404 on a bad path. Without the v prefix it quietly serves a version list instead of the module —

• /module/terraform-aws-modules/iam/aws/v3.12.0 → "Viewing version v3.12.0" ✅
• /module/terraform-aws-modules/iam/aws/3.12.0 → falls back to a version index ❌
• /module/terraform-aws-modules/iam/aws/v3.12.0/submodule/iam-account → "Submodule: iam-account" ✅

An HTTP status check would have reported the broken URL as fine. This is the same soft-404 trap noted in #480 and #444.

Verification

• Terraform output is unchanged: the existing module-generator snapshots — 9 tests, 10 snapshots, including a //modules/ submodule source — pass untouched.
• 7 new Registry unit tests for both registries, pinned and latest, submodule and not.
• 6 new generator-level tests covering the wiring end to end: nothing declared → Terraform, both declared → Terraform, OpenTofu-only → OpenTofu, submodule segment, and a local ./module still rendering "Source at". These drive ModuleGenerator directly, so unlike the existing module tests they need no network or terraform binary.
• @cdktn/commons 101 tests pass; @cdktn/provider-generator builds clean.

Note on a behaviour change

For release notes: a module source whose // path is not a direct child of modules/ (for example //examples/foo or //modules/x/y) used to render a version-less link with the // kept (…/modules/ns/name/tgt//examples/foo), which neither registry serves. It now links to the module's own versioned page. Deep links are emitted only for //modules/<name>, the one shape both registries serve as a page; checked against rendered pages, /submodules/examples/complete is a 404 on the Terraform Registry and an error page on OpenTofu. //modules/<name> sources render exactly as before.

The generic "based on a Terraform module" wording is deliberately left alone — it names the HCL construct, not a registry.

🤖 Generated with Claude Code

[so0k]

Test-focused pass, comments inline.

For release notes: a module source with a // path outside modules/ used to render a version-less link with the // kept (…/modules/ns/name/tgt//examples/foo). It now renders …/modules/ns/name/tgt/<version>/submodules/examples/foo.

[jsteinich]

Re the release-notes point in the review summary: thanks. That note was out of date once the rule changed, and the PR description now has the corrected version: any // path that isn't a direct child of modules/ links to the module's versioned page. //modules/<name> renders exactly as before.

[so0k]

Follow-up (non-blocking): version ranges produce broken module links.

moduleDocsUrl (packages/@cdktn/commons/src/registry.ts:51 and :80) inserts target.version into the URL as written in cdktf.json, where ranges are common.

For example, "~> 19.0" from examples/go/aws/cdktf.json yields https://search.opentofu.org/module/terraform-aws-modules/eks/aws/v~> 19.0.

The space also splits the {@link}, so the link text becomes 19.0 terraform-aws-modules/eks/aws.

Terraform links on main already break the same way, so this PR does not introduce the defect; it carries it over to the OpenTofu URL.

Suggested fix for both registries:

use the version only when it is an exact semver, and fall back to latest otherwise.

That changes Terraform output for projects that use ranges, so it needs its own release note and is better handled as a separate issue than in this PR.

Tests (test-audit, nit):

the "nothing declared" and "OpenTofu only" cases in module-docs-registry.test.ts duplicate registry.test.ts and the target-versions wiring test, so the "OpenTofu Registry" prose assertion could move into the wiring test. The //examples/complete and //modules/x/y cases are the ones that guard this fix.

[jsteinich]

Thanks — agreed it's pre-existing on the Terraform side and needs a release note, so it's tracked separately as #526, with a fix ready to follow this PR: exact versions (with a leading = allowed) are kept, and anything else links to latest, which I'd confirmed is a real page on both registries. I've folded the test-audit nit into that change rather than pushing here, so your approval stands: the two duplicated cases go, the "OpenTofu Registry" prose assertion moves into the wiring test, and a new case checks that a ranged version keeps the {@link} intact.