Fix crash with terraform modules using host:port sources

[jurre]

What

Fixes #12782

When a Terraform module source includes a port in the hostname (e.g., registry.terraform.io:443/terraform-aws-modules/vpc/aws), the RegistryClient#url_for method crashes with URI::InvalidComponentError.

Why

Ruby's URI#host= only accepts a hostname, not host:port. The url_for method was assigning the full hostname string (which may include a port) directly to uri.host:

uri.host = hostname  # hostname = "registry.terraform.io:443" → crash!

How

Split the hostname into host and port components before assigning them to the URI:

host, port = hostname.split(":", 2)
uri.host = host
uri.port = port.to_i if port

This is the minimal fix — it keeps hostname as-is throughout the class (preserving token lookup in headers_for) and only splits when constructing URIs.

Local verification

Reproduced the issue end-to-end with the Dependabot CLI using a local repo containing the exact manifest from the issue:

Before (published image):

updater | +-------------------------------+---------------+
updater | | terraform-aws-modules/vpc/aws | unknown_error |
updater | +-------------------------------+---------------+

After (rebuilt image with fix):

updater | +---------+-------------------------------------------------------+
updater | | created | terraform-aws-modules/vpc/aws ( from 5.5.1 to 6.6.0 ) |
updater | +---------+-------------------------------------------------------+

[Copilot]

Pull request overview

Fixes a Terraform registry client crash when module sources include host:port by correctly separating host and port when constructing service URLs, and adds regression coverage.

Changes:

• Update RegistryClient#url_for to split hostname into host and port before assigning to URI.
• Add a registry client spec covering hostname values that include a port.
• Add a Terraform fixture + parser spec asserting registry_hostname preserves the port from registry sources.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
terraform/lib/dependabot/terraform/registry_client.rb	Fix URI construction for registries configured as host:port.
terraform/spec/dependabot/terraform/registry_client_spec.rb	Regression spec ensuring service discovery + module version fetch uses the configured port.
terraform/spec/dependabot/terraform/file_parser_spec.rb	Spec ensuring registry module sources with ports are parsed into registry_hostname correctly.
terraform/spec/fixtures/projects/registry_with_port/main.tf	Fixture project containing a module source with registry.terraform.io:443/....

[AbhishekBhaskar]

LGTM