feat: add list-allowed-values command and visitor

[david-waltermire]

Summary

• Migrate AllowedValueCollectingNodeItemVisitor from liboscal-java to core module at dev.metaschema.core.metapath.item.node, making it available to all Metaschema users
• Add list-allowed-values CLI command that generates a YAML listing of allowed-values constraints for any Metaschema module
• Register the new command in MetaschemaCommands and the module-info service provider

Motivation

The visitor and command were previously in liboscal-java and oscal-cli respectively, but contain zero OSCAL-specific logic. All imports are dev.metaschema.core.* types. Moving them to metaschema-java makes this functionality available to all Metaschema-based projects.

Changes

File	Change
core/.../AllowedValueCollectingNodeItemVisitor.java	New - visitor migrated from liboscal-java with Javadoc added
core/.../AllowedValueCollectingNodeItemVisitorTest.java	New - 3 tests using mock model builder infrastructure
metaschema-cli/.../ListAllowedValuesCommand.java	New - CLI command following GenerateDiagramCommand pattern
metaschema-cli/.../MetaschemaCommands.java	Register new command
metaschema-cli/module-info.java	Add requires for Jackson YAML and provides entry
metaschema-cli/.../CLITest.java	Add help and execution test cases

Test plan

• AllowedValueCollectingNodeItemVisitorTest - 3 tests (finds constraints, empty for no constraints, handles multiple)
• CLITest - list-allowed-values --help returns OK
• CLITest - list-allowed-values <module> returns OK with YAML output
• Full CI build: mvn clean install -PCI -Prelease passes
• Manual CLI verification: correct YAML output for test module

Summary by CodeRabbit

• New Features

  • Added "list-allowed-values" CLI command to produce YAML reports of allowed-values constraints (locations, targets, values).
  • Introduced a module-level mechanism to collect and organize allowed-values constraints for downstream reporting.

• Tests

  • Added unit tests validating the collector and CLI output (help, usage, and YAML generation).

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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📝 Walkthrough

Walkthrough

Adds a visitor that collects allowed-values constraints from Metaschema modules and a CLI command that emits those collected constraints as structured YAML; includes tests and module descriptor updates.

Changes

Cohort / File(s)	Summary
Visitor Implementation core/src/main/java/dev/metaschema/core/metapath/item/node/AllowedValueCollectingNodeItemVisitor.java	New public visitor class that traverses module node items (flags, fields, assemblies), applies Let-bindings to build DynamicContext, evaluates allowed-values targets, and aggregates results into NodeItemRecord and AllowedValuesRecord collections accessible via getAllowedValueLocations().
Visitor Tests core/src/test/java/dev/metaschema/core/metapath/item/node/AllowedValueCollectingNodeItemVisitorTest.java	New test suite covering discovery of allowed-values constraints, absence of constraints, and multiple-constraint scenarios using mocked module builders.
CLI Command metaschema-cli/src/main/java/dev/metaschema/cli/commands/ListAllowedValuesCommand.java	New terminal command list-allowed-values that loads a module, invokes the visitor to collect constraints, and emits a YAML report grouped by target definition; supports stdout or file output and includes error handling for IO and argument issues.
CLI Registry & Module Descriptor metaschema-cli/src/main/java/dev/metaschema/cli/commands/MetaschemaCommands.java, metaschema-cli/src/main/java/module-info.java	Registers the new ListAllowedValuesCommand in the command registry and adds com.fasterxml.jackson.dataformat.yaml to module requirements; exposes the new command in the module provides block.
CLI Tests metaschema-cli/src/test/java/dev/metaschema/cli/CLITest.java	Adds CLI test invocations for list-allowed-values --help and execution that writes YAML output; includes assertion of generated YAML content.

Sequence Diagram

sequenceDiagram
    participant User as User/CLI
    participant Cmd as ListAllowedValuesCommand
    participant Loader as Module Loader
    participant Visitor as AllowedValueCollectingNodeItemVisitor
    participant Module as IModule
    participant YAML as YAML Generator
    participant Output as File/Stdout

    User->>Cmd: list-allowed-values module.xml [output.yaml]
    Cmd->>Loader: resolve & load module
    Loader->>Module: parse module
    Cmd->>Visitor: create visitor with context
    Cmd->>Visitor: visit(module)
    Visitor->>Module: traverse node items (flags/fields/assemblies)
    Visitor->>Visitor: apply Let-bindings, evaluate targets
    Visitor->>Visitor: collect AllowedValuesRecords into NodeItemRecords
    Visitor-->>Cmd: return collected records
    Cmd->>YAML: generate structured YAML grouped by target
    YAML->>Output: write to file or stdout
    Output-->>User: display/save results

Loading

Estimated Code Review Effort

🎯 4 (Complex) | ⏱️ ~55 minutes

Poem

🐰 I hop through schemas, sniffing each rule,
Gathering values from field, flag, and tool,
I bind all the Lets and follow each trail,
Spit out some YAML — happy tails prevail! 🥕✨

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 43.48% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title accurately describes the main changes: adding a list-allowed-values command and a visitor component for extracting allowed-values constraints from Metaschema modules.
Merge Conflict Detection	✅ Passed	✅ No merge conflicts detected when merging into develop

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 PMD (7.21.0)

metaschema-cli/src/test/java/dev/metaschema/cli/CLITest.java

[ERROR] Cannot load ruleset pmd/category/java/custom.xml: Cannot resolve rule/ruleset reference 'pmd/category/java/custom.xml'. Make sure the resource is a valid file or URL and is on the CLASSPATH. Use --debug (or a fine log level) to see the current classpath.
[WARN] Progressbar rendering conflicts with reporting to STDOUT. No progressbar will be shown. Try running with argument -r to output the report to a file instead.

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[coderabbitai]

🧹 Nitpick comments (1)

core/src/main/java/dev/metaschema/core/metapath/item/node/AllowedValueCollectingNodeItemVisitor.java (1)

188-196: Consider returning an unmodifiable list from getAllowedValues.
This prevents external mutation of the internal collection while preserving the addAllowedValues API.

♻️ Suggested change

 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@
   `@NonNull`
   public List<AllowedValuesRecord> getAllowedValues() {
-    return allowedValues;
+    return Collections.unmodifiableList(allowedValues);
   }