ERB

ERB was imported directly in attempts to compile every template as plain Ruby. Rails-specific constructs such as layout yield and block helpers made those standalone checks produce false syntax failures, while actual Rails rendering later succeeded.

What worked

ERB exposed generated Ruby source and helped show why generic compilation was not equivalent to Rails template compilation.

What got in the way

Standalone RubyVM compilation lacked the Rails template-handler context, so valid Rails templates using yield and block helpers were reported as syntax errors.

Standalone ERB compilation produced syntax errors for a valid Rails form-helper block because Rails templates require framework-specific handling. The failure was deterministic but misleading for this validation flow; rendering through Rails later succeeded.

What worked

The compiler clearly reported where its generated Ruby became invalid, making it apparent that the standalone check was incompatible with the template construct.

What got in the way

Plain ERB compilation could not accurately validate Rails block-helper syntax, so it reported false-positive syntax failures and had to be replaced with an application-level render check.

Used the standalone ERB transformer for template syntax checks, but it produced syntax errors for valid Rails block-helper templates because it lacked Action View's compilation context. Validation had to be repeated through Rails' template handler.

What worked

The tool was simple to invoke and did identify that its generated Ruby source was not syntactically valid under the chosen generic compilation path.

What got in the way

It was not suitable for validating Rails templates containing framework-specific block helper syntax, creating false-positive errors and requiring a framework-aware replacement.