feat(module): add QuickJS extended JSON modules

Author: doodlewind

README.md

@@ -14,8 +14,9 @@ module-host callbacks can synchronously compile and return same-Context
 modules, including nested loader re-entry protected by a finite host-stack
 budget. Parse-in-progress module identities and source-order request prefixes
 are visible to those callbacks in QuickJS order, with unsafe failed identities
-represented deterministically. JSON5/byte-oriented loading and the remaining
-conformance gaps are still parity work.
+represented deterministically. QuickJS extended-JSON text modules are
+supported; byte-oriented loading and the remaining conformance gaps are still
+parity work.
 
 <!-- current-test262-metrics:start -->
 The authoritative R3eu Test262 baseline records **79,475 full-corpus passes
@@ -45,6 +46,10 @@ cargo run --quiet --bin qjs -- --print-result -e \
 cargo run --quiet --bin qjs -- examples/module-42.mjs  # 42
 ```
 
+The file loader follows QuickJS policy: `.json` is strict JSON,
+`type: "json5"` selects QuickJS extended JSON for any suffix, and a `.json5`
+file without that attribute remains a JavaScript module.
+
 ## Status
 
 - [Current implementation status](docs/status.md)

docs/status.md

@@ -38,8 +38,8 @@ The exact profile, inputs, summary, line counts, and report hashes live in
   QuickJS-matched early errors
 - static-module graphs, live namespaces, default exports, top-level await with
   async dependency/SCC scheduling, static import attributes with loader
-  validation, JSON synthetic modules, and canonical host-populated
-  `import.meta` objects
+  validation, strict and QuickJS-extended JSON synthetic modules, and
+  canonical host-populated `import.meta` objects
 - Script-goal dynamic `import()` with FIFO load/finish jobs, live host-loader
   callback sampling, import attributes, cached cycle-root evaluation Promises,
   namespace reuse, Promise assimilation, and exact propagation of arbitrary
@@ -64,9 +64,10 @@ host is isolated behind a non-default feature.
 
 ## Remaining parity work
 
-Major open frontiers include JSON5/byte-oriented host loading, remaining
-module-host lifetime and allocation-failure edge matrices, and the
-unsupported/failed leaves recorded by the current Test262 vector. Failed
+Major open frontiers include raw-byte module payloads such as malformed UTF-8
+and WTF-8, remaining module-host lifetime and allocation-failure edge matrices,
+and the unsupported/failed leaves recorded by the current Test262 vector.
+Failed
 acyclic source graphs retry like QuickJS. Parse-time resolution success and
 one-shot failure latches match the pinned callback order; an incomplete graph
 is non-executable and dynamic import rejects deterministically. Rust safely

src/main.rs

@@ -61,6 +61,9 @@ impl ModuleLoader for FileModuleLoader {
             .map_err(|_| ModuleLoaderError::new("module filename is not valid Unicode"))?;
         let source = std::fs::read_to_string(&filename)
             .map_err(|_| ModuleLoaderError::new(format!("module filename '{filename}'")))?;
+        if import_type_is(attributes, "json5") {
+            return Ok(ModuleLoadResult::Json5Text(source));
+        }
         if filename.ends_with(".json") || import_type_is(attributes, "json") {
             return Ok(ModuleLoadResult::JsonText(source));
         }