gradle: fix wrapper updater crash when only some wrapper files define checksum

[pedromfmachado]

Problem

Dependabot crashes updating gradle-wrapper in repositories with multiple gradle-wrapper.properties files when only some files include distributionSha256Sum.

Error:

• Error processing gradle-wrapper (TypeError)
• T.let: Expected type String, got type NilClass

Root cause

WrapperUpdater#command_args used a global guard:

• dependency.requirements.size > 1

but indexed into the local per-file slice:

• requirements[1]

In mixed multi-wrapper scenarios, a local file can have only one requirement (distributionUrl), so requirements[1] is nil and Sorbet raises.

Fix

Use a local guard and nullable type for checksum extraction:

• checksum = T.let(requirements[1]&.[](:requirement), T.nilable(String)) if requirements.size > 1

This keeps behavior for single-wrapper repositories unchanged and prevents the crash for mixed multi-wrapper repositories.

Test coverage

Added a focused regression spec:

• gradle/spec/dependabot/gradle/file_updater/wrapper_updater_spec.rb

Scenario covered:

• dependency has merged requirements for two wrapper files
• current file has only distributionUrl
• another file has distributionUrl + distributionSha256Sum

Assertion:

• no checksum argument is added for the file without checksum and no crash occurs.

Testing

bin/test gradle spec/dependabot/gradle/file_updater/wrapper_updater_spec.rb spec/dependabot/gradle/file_updater_spec.rb --example wrapper

Result:

• 5 examples, 0 failures

[kbukum1]

LGTM