1 files changed, 70 insertions, 0 deletions
diff --git a/node_modules/@ava/babel-plugin-throws-helper/index.js b/node_modules/@ava/babel-plugin-throws-helper/index.js
new file mode 100644
index 000000000..e370480f1
--- /dev/null
+++ b/node_modules/@ava/babel-plugin-throws-helper/index.js
@@ -0,0 +1,70 @@
+'use strict';
+
+module.exports = babelCore => {
+	const t = babelCore.types;
+	const wrapArg = babelCore.template('(START(t, ASSERTION, FILE, LINE), END(t, ARG))');
+	const helpers = babelCore.template(`function START(t, assertion, file, line) {
+  if (t._throwsArgStart) {
+    t._throwsArgStart(assertion, file, line);
+  }
+}
+
+function END(t, arg) {
+  if (t._throwsArgEnd) {
+    t._throwsArgEnd();
+  }
+
+  return arg;
+}`);
+
+	const assertionVisitor = {
+		CallExpression(path, state) {
+			const callee = path.get('callee');
+			if (!callee.isMemberExpression() || !callee.get('object').isIdentifier({name: 't'}) || !callee.get('property').isIdentifier()) {
+				return;
+			}
+
+			const assertion = callee.get('property').get('name').node;
+			if (assertion !== 'throws' && assertion !== 'notThrows') {
+				return;
+			}
+
+			const arg0 = path.node.arguments[0];
+			if (!(arg0 && arg0.loc && (typeof arg0.start === 'number') && (typeof arg0.end === 'number'))) {
+				return;
+			}
+
+			// Wrap the argument expression, so that the stack trace of the assertion
+			// isn't affected.
+			path.node.arguments[0] = wrapArg(Object.assign({
+				ARG: arg0,
+				ASSERTION: t.stringLiteral(assertion),
+				FILE: t.stringLiteral(state.file.opts.filename),
+				LINE: t.numericLiteral(arg0.loc.start.line)
+			}, this.installHelper())).expression;
+		}
+	};
+
+	return {
+		visitor: {
+			Program(path, state) {
+				const START = t.identifier(path.scope.generateUid('avaThrowsHelperStart'));
+				const END = t.identifier(path.scope.generateUid('avaThrowsHelperEnd'));
+				const helperIdentifiers = {START, END};
+
+				let created = false;
+				path.traverse(assertionVisitor, {
+					installHelper() {
+						if (!created) {
+							created = true;
+							path.unshiftContainer('body', helpers(helperIdentifiers));
+						}
+
+						return helperIdentifiers;
+					},
+					file: state.file
+				});
+			}
+		}
+	};
+};