feat(napi/transform): add TransformerOptions::assumptions (#7601)

so that I can use `setPublicClassFields` for #6735 when it's ready.

crates/oxc/src/napi/transform.rs

@@ -74,6 +74,9 @@ pub struct TransformOptions {
     /// @see {@link SourceMap}
     pub sourcemap: Option<bool>,
 
+    /// Set assumptions in order to produce smaller output.
+    pub assumptions: Option<CompilerAssumptions>,
+
     /// Configure how TypeScript is transformed.
     pub typescript: Option<TypeScriptOptions>,
 
@@ -114,6 +117,7 @@ impl TryFrom<TransformOptions> for oxc_transformer::TransformOptions {
         };
         Ok(Self {
             cwd: options.cwd.map(PathBuf::from).unwrap_or_default(),
+            assumptions: options.assumptions.map(Into::into).unwrap_or_default(),
             typescript: options
                 .typescript
                 .map(oxc_transformer::TypeScriptOptions::from)
@@ -125,6 +129,36 @@ impl TryFrom<TransformOptions> for oxc_transformer::TransformOptions {
     }
 }
 
+#[napi(object)]
+#[derive(Default, Debug)]
+pub struct CompilerAssumptions {
+    pub ignore_function_length: Option<bool>,
+    pub no_document_all: Option<bool>,
+    pub object_rest_no_symbols: Option<bool>,
+    pub pure_getters: Option<bool>,
+    pub set_public_class_fields: Option<bool>,
+}
+
+impl From<CompilerAssumptions> for oxc_transformer::CompilerAssumptions {
+    fn from(value: CompilerAssumptions) -> Self {
+        let ops = oxc_transformer::CompilerAssumptions::default();
+        Self {
+            ignore_function_length: value
+                .ignore_function_length
+                .unwrap_or(ops.ignore_function_length),
+            no_document_all: value.no_document_all.unwrap_or(ops.no_document_all),
+            object_rest_no_symbols: value
+                .object_rest_no_symbols
+                .unwrap_or(ops.object_rest_no_symbols),
+            pure_getters: value.pure_getters.unwrap_or(ops.pure_getters),
+            set_public_class_fields: value
+                .set_public_class_fields
+                .unwrap_or(ops.set_public_class_fields),
+            ..ops
+        }
+    }
+}
+
 #[napi(object)]
 #[derive(Default)]
 pub struct TypeScriptOptions {

napi/transform/index.d.ts

@@ -12,6 +12,14 @@ export interface ArrowFunctionsOptions {
   spec?: boolean
 }
 
+export interface CompilerAssumptions {
+  ignoreFunctionLength?: boolean
+  noDocumentAll?: boolean
+  objectRestNoSymbols?: boolean
+  pureGetters?: boolean
+  setPublicClassFields?: boolean
+}
+
 export interface Es2015Options {
   /** Transform arrow functions into function expressions. */
   arrowFunction?: ArrowFunctionsOptions
@@ -199,6 +207,8 @@ export interface TransformOptions {
    * @see {@link SourceMap}
    */
   sourcemap?: boolean
+  /** Set assumptions in order to produce smaller output. */
+  assumptions?: CompilerAssumptions
   /** Configure how TypeScript is transformed. */
   typescript?: TypeScriptOptions
   /** Configure how TSX and JSX are transformed. */