receive and fallback support (#244)

* receive and fallback support

* 2 more cases

* A more explicit return of 'fallback' and 'function'

* use a map

Co-authored-by: mattia richetto <mattia.richetto@gmail.com>

Author: Janther

src/nodes/FunctionDefinition.js

@@ -6,10 +6,21 @@ const {
 
 const printList = require('./print-list');
 
-const functionName = node => {
+const functionName = (node, options) => {
   if (node.isConstructor && !node.name) return 'constructor';
   if (node.name) return `function ${node.name}`;
-  return 'function';
+  if (node.isReceiveEther) return 'receive';
+  // The parser doesn't give us any information about the keyword used for the
+  // fallback.
+  // Using the originalText is the next best option.
+  // A neat idea would be to rely on the pragma and enforce it but for the
+  // moment this will do.
+  const names = { fallback: 'fallback', function: 'function' };
+  const name = options.originalText.slice(
+    options.locStart(node),
+    options.locStart(node) + 8
+  );
+  return names[name];
 };
 
 const parameters = (parametersType, node, path, print) =>
@@ -49,9 +60,9 @@ const signatureEnd = node => (node.body ? dedent(line) : ';');
 const body = (node, path, print) => (node.body ? path.call(print, 'body') : '');
 
 const FunctionDefinition = {
-  print: ({ node, path, print }) =>
+  print: ({ node, path, print, options }) =>
     concat([
-      functionName(node),
+      functionName(node, options),
       '(',
       parameters('parameters', node, path, print),
       ')',

tests/FunctionDefinitions/FunctionDefinitions.sol

@@ -37,6 +37,13 @@ interface FunctionInterfaces {
 }
 
 contract FunctionDefinitions {
+  function () external {}
+  fallback () external {}
+
+  function () external payable {}
+  fallback () external payable {}
+  receive () external payable {}
+
   function noParamsNoModifiersNoReturns() {
     a = 1;
   }

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

@@ -40,6 +40,13 @@ interface FunctionInterfaces {
 }
 
 contract FunctionDefinitions {
+  function () external {}
+  fallback () external {}
+
+  function () external payable {}
+  fallback () external payable {}
+  receive () external payable {}
+
   function noParamsNoModifiersNoReturns() {
     a = 1;
   }
@@ -323,6 +330,16 @@ interface FunctionInterfaces {
 
 
 contract FunctionDefinitions {
+    function() external {}
+
+    fallback() external {}
+
+    function() external payable {}
+
+    fallback() external payable {}
+
+    receive() external payable {}
+
     function noParamsNoModifiersNoReturns() {
         a = 1;
     }