This PR implements automatic wrapping of string literals in JSX children withJsx.string() calls, eliminating the need for manual wrapping.

Problem

Currently, string literals in JSX children must be explicitly wrapped:

// Current - requires manual wrapping<span>{Jsx.string("hello")}</span><> {Jsx.string("world")} </>// What developers want to write<span>hello</span><>world </>

Solution

Modified the JSX children parser incompiler/syntax/src/res_core.ml to automatically detect string literals and wrap them withJsx.string() calls during AST construction.

Implementation Details

1. Addedwrap_jsx_string_literal function that:

   • Detects string literal expressions (Pexp_constant (Pconst_string ...))
   • Creates AST nodes representingJsx.string(originalString) function calls
   • Preserves original source location information

2. Integrated intoparse_jsx_children:

   • Applied to both JSX parsing paths (element and fragment children)
   • Only affects direct string literals, not expressions in braces
   • Maintains backward compatibility with existing code

Examples

After this change, the following transformations happen automatically:

// Input<span>helloworld</span>// Parsed as equivalent to<span>{Jsx.string("hello world")}</span>// Input<>fragmenttext </>// Parsed as equivalent to<> {Jsx.string("fragment text")} </>// Input<div>first<span>nested</span>last</div>// Parsed as equivalent to<div>{Jsx.string("first")}<span>{Jsx.string("nested")}</span>{Jsx.string("last")}</div>

Backward Compatibility

• Existing explicitly wrapped strings continue to work unchanged:<span>{Jsx.string("hello")}</span>
• Expressions in braces remain unaffected:<span>{someVariable}</span>
• Only bare string literals get automatically wrapped

Test Cases

Added comprehensive test cases totests/syntax_tests/data/parsing/grammar/expressions/jsx.res covering:

• Basic string literals in JSX elements
• String literals in JSX fragments
• Multiple string literals with nested elements
• Mixed content scenarios

The implementation follows established patterns in the ReScript compiler codebase and maintains full compatibility with existing JSX usage patterns.

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