CAMEL-22894: Extract sys/env, date, properties, ref, type, messageAs, pretty/toJson Simple functions into dedicated factories

[ammachado]

Description

Continues the CAMEL-22894 series, which extracts inline Simple language function dispatch from the monolithic SimpleFunctionExpression into dedicated SimpleLanguageFunctionFactory implementations.

This PR covers six new factory classes:

Factory	Functions handled
SystemFunctionFactory	${sys.name}, ${sysenv.name}, ${sysenv:name}, ${env.name}, ${env:name}
PropertiesFunctionFactory	${propertiesExist:key}, ${properties:key}, ${properties:key:default}, ${ref:name}
TypeFunctionFactory	${type:fqn}, ${type:fqn.FIELD}
DateFunctionFactory	${date:command}, ${date:command:pattern}, ${date-with-timezone:command:timezone:pattern} (including date:millis code-gen special case)
MessageFunctionFactory	${messageAs(type)}, ${messageAs(type).OGNL}
OutputFunctionFactory	${pretty(exp)}, ${toJson(exp)}, ${toPrettyJson(exp)}

All factories follow the established pattern: createFunction() for runtime evaluation, createCode() (deprecated, csimple only) for code generation where applicable. MessageFunctionFactory and OutputFunctionFactory omit createCode() since csimple never supported those functions.

Also removes the two @Deprecated(forRemoval = true) methods tryCreate() and tryCreateCode() from SimpleFunctionDispatcher, which were confirmed unused.

SimpleFunctionExpression shrinks by ~160 lines after this PR.

Test changes

Tests for the six factories are moved out of the monolithic SimpleTest into dedicated per-factory test classes under o.a.c.language.simple.functions. Notable refinements:

• SystemFunctionFactoryTest uses JUnit Pioneer's @SetSystemProperty (added junit-pioneer dependency to camel-core) to safely scope the property to the test method.
• MessageFunctionFactoryTest documents a subtle semantic: messageAs(T) returns null at the expression layer when the type conversion fails; the Simple predicate engine then coerces null to false. The original SimpleTest only tested the predicate layer, masking this.
• OutputFunctionFactoryTest documents the XmlPrettyPrinter behavior where text content directly inside the root element is silently dropped (only emitted when indent > 1).

Target

• I checked that the commit is targeting the correct branch (Camel 4 uses the main branch)

Tracking

• If this is a large change, bug fix, or code improvement, I checked there is a JIRA issue filed for the change (usually before you start working on it).

Apache Camel coding standards and style

• I checked that each commit in the pull request has a meaningful subject line and body.
• I have run mvn clean install -DskipTests locally from root folder and I have committed all auto-generated changes.

Claude Code on behalf of Adriano Machado

[github-actions]

🌟 Thank you for your contribution to the Apache Camel project! 🌟
🤖 CI automation will test this PR automatically.

🐫 Apache Camel Committers, please review the following items:

• First-time contributors require MANUAL approval for the GitHub Actions to run
• You can use the command /component-test (camel-)component-name1 (camel-)component-name2.. to request a test from the test bot although they are normally detected and executed by CI.
• You can label PRs using skip-tests and test-dependents to fine-tune the checks executed by this PR.
• Build and test logs are available in the summary page. Only Apache Camel committers have access to the summary.

⚠️ Be careful when sharing logs. Review their contents before sharing them publicly.

[davsclaus]

Clean extraction of six more Simple function families into dedicated factories, continuing the CAMEL-22894 series. All factories faithfully reproduce the original dispatch logic from SimpleFunctionExpression.

Verified:

• tryCreate() / tryCreateCode() removals are safe — confirmed no external callers
• Dead parts.length > 2 validation in propertiesExist: correctly dropped (split with limit 2 can never exceed 2 elements)
• TypeFunctionFactory preserves the init() + cacheExpression() wrapping
• OutputFunctionFactory prefix ordering is correct
• Test coverage is thorough — MessageFunctionFactoryTest documents the subtle null-vs-false semantic, SystemFunctionFactoryTest uses JUnit Pioneer @SetSystemProperty properly

Minor observation (non-blocking): PropertiesFunctionFactory.createCode() still has the same dead parts.length > 2 check (line ~42 in the factory). Not a regression, just a cleanup opportunity.

LGTM.

This review was generated by an AI agent and may contain inaccuracies. Please verify all suggestions before applying.

[github-actions]

🧪 CI tested the following changed modules:

• core/camel-core
• core/camel-core-languages
• core/camel-core

ℹ️ Dependent modules were not tested because the total number of affected modules exceeded the threshold (50). Use the test-dependents label to force testing all dependents.

✅ POM dependency changes: targeted tests included

Modules affected by dependency changes (2)

• :camel-core
• :camel-core-languages

⚠️ Some tests are disabled on GitHub Actions (@DisabledIfSystemProperty(named = "ci.env.name")) and require manual verification:

• core/camel-core: 2 test(s) disabled on GitHub Actions
• core/camel-core: 2 test(s) disabled on GitHub Actions

Build reactor — dependencies compiled but only changed modules were tested (2 modules)

• Camel :: Core
• Camel :: Core Languages

---

⚙️ View full build and test results