Fix emitted package.json structure (#4091)

CHANGELOG.md

@@ -18,6 +18,9 @@
   [#4082](https://github.com/rustwasm/wasm-bindgen/pull/4082)
   [#4088](https://github.com/rustwasm/wasm-bindgen/pull/4088)
 
+* Fixed emitted `package.json` structure to correctly specify its dependencies
+  [#4091](https://github.com/rustwasm/wasm-bindgen/pull/4091)
+
 --------------------------------------------------------------------------------
 
 ## [0.2.93](https://github.com/rustwasm/wasm-bindgen/compare/0.2.92...0.2.93)

crates/cli-support/Cargo.toml

@@ -18,6 +18,7 @@ anyhow = "1.0"
 base64 = "0.22"
 log = "0.4"
 rustc-demangle = "0.1.13"
+serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tempfile = "3.0"
 unicode-ident = "1.0.5"

crates/cli-support/src/lib.rs

@@ -641,12 +641,18 @@ impl Output {
         }
 
         if !gen.npm_dependencies.is_empty() {
-            let map = gen
-                .npm_dependencies
-                .iter()
-                .map(|(k, v)| (k, &v.1))
-                .collect::<BTreeMap<_, _>>();
-            let json = serde_json::to_string_pretty(&map)?;
+            #[derive(serde::Serialize)]
+            struct PackageJson<'a> {
+                dependencies: BTreeMap<&'a str, &'a str>,
+            }
+            let pj = PackageJson {
+                dependencies: gen
+                    .npm_dependencies
+                    .iter()
+                    .map(|(k, v)| (k.as_str(), v.1.as_str()))
+                    .collect(),
+            };
+            let json = serde_json::to_string_pretty(&pj)?;
             fs::write(out_dir.join("package.json"), json)?;
         }