Add support for parsing babylons throwExpressions (#4695)

src/language-js/parser-babylon.js

@@ -31,7 +31,8 @@ function parse(text, parsers, opts) {
       "optionalChaining",
       "classPrivateProperties",
       "pipelineOperator",
-      "nullishCoalescingOperator"
+      "nullishCoalescingOperator",
+      "throwExpressions"
     ]
   };
 

tests/throw_expressions/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`throw_expression.js 1`] = `
+function save(filename = throw new TypeError("Argument required")) {}
+
+lint(ast, {
+  with: () => throw new Error("avoid using 'with' statements.")
+});
+
+function getEncoder(encoding) {
+  const encoder = encoding === "utf8" ? new UTF8Encoder()
+                : encoding === "utf16le" ? new UTF16Encoder(false)
+                : encoding === "utf16be" ? new UTF16Encoder(true)
+                : throw new Error("Unsupported encoding");
+}
+
+class Product {
+  get id() { return this._id; }
+  set id(value) { this._id = value || throw new Error("Invalid value"); }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+function save(filename = throw new TypeError("Argument required")) {}
+
+lint(ast, {
+  with: () => throw new Error("avoid using 'with' statements.")
+});
+
+function getEncoder(encoding) {
+  const encoder =
+    encoding === "utf8"
+      ? new UTF8Encoder()
+      : encoding === "utf16le"
+        ? new UTF16Encoder(false)
+        : encoding === "utf16be"
+          ? new UTF16Encoder(true)
+          : throw new Error("Unsupported encoding");
+}
+
+class Product {
+  get id() {
+    return this._id;
+  }
+  set id(value) {
+    this._id = value || throw new Error("Invalid value");
+  }
+}
+
+`;

tests/throw_expressions/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, ["babylon"]);

tests/throw_expressions/throw_expression.js

@@ -0,0 +1,17 @@
+function save(filename = throw new TypeError("Argument required")) {}
+
+lint(ast, {
+  with: () => throw new Error("avoid using 'with' statements.")
+});
+
+function getEncoder(encoding) {
+  const encoder = encoding === "utf8" ? new UTF8Encoder()
+                : encoding === "utf16le" ? new UTF16Encoder(false)
+                : encoding === "utf16be" ? new UTF16Encoder(true)
+                : throw new Error("Unsupported encoding");
+}
+
+class Product {
+  get id() { return this._id; }
+  set id(value) { this._id = value || throw new Error("Invalid value"); }
+}