[so0k]

Related issue

Fixes #216

Description

Root cause. cdktn get fails under OpenTofu (TERRAFORM_BINARY_NAME=tofu) with Could not find provider with constraint ..., even though the provider installs correctly. The failure is in provider-schema → target matching, not in provider download.

In packages/@cdktn/provider-generator/src/get/generator/provider-generator.ts, isMatching expands a target source and compares it to the schema key. When a source omits a registry hostname (a shorthand like hashicorp/awscc), the old code assumed the missing hostname was always registry.terraform.io and compared it strictly against the schema key's hostname:

• Terraform resolves hashicorp/awscc → schema key registry.terraform.io/hashicorp/awscc ✅
• OpenTofu resolves hashicorp/awscc → schema key registry.opentofu.org/hashicorp/awscc ❌ (never matched)

Fix (minimal, intentionally). Only compare the hostname when the source explicitly pins one (a 3-part source). Shorthand 1- and 2-part sources now match on namespace/name and ignore the schema key's registry hostname:

const explicitHostname = targetElements.length === 3;
return (
  (!explicitHostname || targetSource.hostname === hostname) &&
  targetSource.namespace === namespace &&
  targetSource.name === provider
);

Why exactly this shape:

• Same cdktf.json works under both CLIs. emitProvider writes terraformProviderSource = constraint.source, so the shorthand hashicorp/awscc is preserved in generated metadata — it stays registry-agnostic instead of being pinned to one registry. This avoids the downside of the documented workaround (registry.opentofu.org/hashicorp/awscc), which hard-codes an OpenTofu-only source address.
• Explicit hostnames stay strict. A 3-part source like registry.terraform.io/hashicorp/awscc still only matches that exact registry and won't cross to registry.opentofu.org.
• Rejected alternatives. Branching on TERRAFORM_BINARY_NAME couples generator logic to the binary and breaks with wrapper scripts/paths. A full "match against actual schema keys + explicit ambiguity error" design adds machinery for a case that can't occur from a single terraform/tofu providers schema run (each provider resolves to exactly one registry per invocation). Per the project's YAGNI > KISS priority, we kept it minimal; getProviderByConstraint uses .find(), so the pathological "same namespace/name under two hostnames" schema would deterministically pick the first key rather than throw — acceptable and not worth building around today.

Scope note. hcl2cdk's separate matcher (packages/@cdktn/hcl2cdk/src/provider.ts) already matches with .endsWith() and is hostname-agnostic, so it is unaffected. This change is deliberately confined to the one matcher on the cdktn get path.

Tests

Added provider-source-matching.test.ts driving TerraformProviderGenerator.generate(...) (since isMatching is module-private) over minimal hand-built schemas:

1. shorthand hashicorp/awscc ↔ registry.opentofu.org/hashicorp/awscc → matches (the cdktn get fails to generate provider bindings when using OpenTofu #216 regression)
2. shorthand hashicorp/awscc ↔ registry.terraform.io/hashicorp/awscc → still matches
3. explicit registry.terraform.io/... ↔ registry.opentofu.org/... → stays strict, throws
4. explicit hostname agreeing with the schema key → matches

Follow-up (out of scope): the repo currently has no integration tests that run with tofu. End-to-end coverage of the OpenTofu cdktn get path is tracked as a separate work item rather than bundled here, to keep this PR small and focused on the matcher fix. The unit tests above prove the matching behavior directly.

Note: the full nx unit suite was not run in the authoring environment (workspace ^build chain was slow); CI runs it here and it will also be validated locally. The change is a single boolean guard plus new tests.

Checklist

• I have updated the PR title to match CDKTN's style guide
• I have run the linter on my code locally (prettier via pre-commit hook)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable (n/a)
• My changes generate no new warnings
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally with my changes (deferred to CI — see note above)

🤖 Generated with Claude Code

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Generated by Claude Code

[jsteinich]

While not matching against the current binary makes sense, we still may want a away in the future for users to be able to explicitly set cdktn into Terraform, OpenTofu, or mixed mode. Can be a follow-up item though.

[github-actions]

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