Issue-782 # Support {{...}} double curly brace based as alternate placeholder delimiter alongside ${...}

[umer901]

Added support for {{...}} double curly braces as alternate placeholder delimiter alongside ${...}

Fixed Which Issue?

• Fixes Issue 782 Support {{...}} double curly brace based as alternate placeholder delimiter alongside ${...} #782

PR Branch
https://github.com/umer901/zerocode/tree/issue-782-support-double-curly-brace

Motivation and Context

Zerocode currently supports ${...} placeholders in test steps, target-env property files, and CSV-parameterized scenarios. This PR adds {{...}} as an equivalent alternative without changing existing ${...} behavior.

Both styles can be used in the same scenario. The implementation covers known runtime tokens, system properties/environment variables, random tokens, masked values, host-property keys, JSON-path values, CSV positional/named PARAM values, and target-env file placeholders.

The change is intentionally scoped to existing placeholder-resolution paths and adds no dependencies.

Implementation:

• Changed the regex in ApplicationMainModule.java‎ and ZeroCodeParameterizedProcessorImpl.java‎
• Updated all comments that mention the placeholders
• Added a replaceTokens helper that passes after existing StringSubstitutor (to avoid adding the {{...}} separately at each site), and
• Updated ZeroCodeAssertionsProcessorImpl.java and SmartUtils to use the shared resolver.
• In token utils, token extraction now captures the parameter name from either bracket format. I also moved the token and masked token regexes from the function to pattern constants.

Tests:

• TokenUtilsTest.java: verifies tokens work with {{...}}, masked values work in double braces, and an unknown Handlebars-shaped token stays literal.
• ZeroCodeAssertionsProcessorImplTest.java: verified double-brace host-property resolution and mixed ${...}/{{...}} JSON-path resolution.
• ZeroCodeParameterizedProcessorImplTest.java: verified double-brace positional and named CSV parameters, plus the missing-header error path.
• ApplicationMainModuleTest.java: verified target-env properties resolve from both delimiter styles and unresolved values remain unchanged.
• SmartUtilsTest.java: verified generic map-based replacement works with double braces.
• Added integration coverage in DoubleBracePlaceholdersInMemoryTest.java which starts the in-memory simulator and executes a real HTTP scenario using {{...}} host-property, CSV PARAM, random, system-property, and masked tokens. It also mixes ${...} and {{...}} in the same scenario and confirms the Handlebars-shaped header remains literal.

Checklist:

• 1. New Unit tests were added

  • 1.1 Covered in existing Unit tests

• 2. Integration tests were added

  • 2.1 Covered in existing Integration tests

• 3. Test names are meaningful

• 3.1 Feature manually tested and outcome is successful

• 4. PR doesn't break any of the earlier features for end users

  • 4.1 WARNING! This might break one or more earlier earlier features, hence left a comment tagging all reviewrs

• 5. PR doesn't break the HTML report features directly

  • 5.1 Yes! I've manually run it locally and seen the HTML reports are generated perfectly fine
  • 5.2 Yes! I've opened the generated HTML reports from the /target folder and they look fine

• 6. PR doesn't break any HTML report features indirectly

  • 6.1 I have not added or amended any dependencies in this PR
  • 6.2 I have double checked, the new dependency added or removed has not affected the report generation indirectly
  • 6.3 Yes! I've seen the Sample report screenshots here, and HTML report of the current PR looks simillar.

• 7. Branch build passed in CI

• 8. No 'package.*' in the imports

• 9. Relevant DOcumentation page added or updated with clear instructions and examples for the end user

  • 9.1 Not applicable. This was only a code refactor change, no functional or behaviourial changes were introduced

• 10. Http test added to http-testing-examples module(if applicable) ?

  • 10.1 Not applicable. The changes did not affect HTTP automation flow

• 11. Kafka test added to kafka-testing-examples module(if applicable) ?

  • 11.1 Not applicable. The changes did not affect Kafka automation flow

I have one question, is there a need to add documentation, and if so where? I reflected the changes in the comments where needed.

[authorjapps]

CI run is is-progress here. Keep an eye please.

[IgnatiosSar]

Looks good to me! Acceptance criteria are met and the implementation is covered by tests.