Fix handling of array slices without start and/or end (#473)

* Upgrade solidity parser

* Handle array slices without start and/or end

Author: fvictorio

package.json

@@ -74,7 +74,7 @@
     "outdent": "^0.8.0"
   },
   "dependencies": {
-    "@solidity-parser/parser": "^0.12.0",
+    "@solidity-parser/parser": "^0.12.1",
     "dir-to-object": "^2.0.0",
     "emoji-regex": "^9.2.1",
     "escape-string-regexp": "^4.0.0",

src/nodes/IndexRangeAccess.js

@@ -5,13 +5,13 @@ const {
 } = require('prettier/standalone');
 
 const IndexRangeAccess = {
-  print: ({ path, print }) =>
+  print: ({ node, path, print }) =>
     concat([
       path.call(print, 'base'),
       '[',
-      path.call(print, 'indexStart'),
+      node.indexStart ? path.call(print, 'indexStart') : '',
       ':',
-      path.call(print, 'indexEnd'),
+      node.indexEnd ? path.call(print, 'indexEnd') : '',
       ']'
     ])
 };

tests/Arrays/Arrays.sol

@@ -7,3 +7,11 @@ contract Arrays {
     Outcome.OutcomeItem[] memory outcomeFrom = abi.decode(fromPart.outcome, (Outcome.OutcomeItem[]));
 }
 }
+
+contract ArraySlices {
+    function f(bytes calldata x) public {
+        bytes memory a1 = abi.decode(x[:], (bytes));
+        bytes4 a2 = abi.decode(x[:4], (bytes4));
+        address a3 = abi.decode(x[4:], (address));
+    }
+}

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

@@ -16,6 +16,14 @@ contract Arrays {
 }
 }
 
+contract ArraySlices {
+    function f(bytes calldata x) public {
+        bytes memory a1 = abi.decode(x[:], (bytes));
+        bytes4 a2 = abi.decode(x[:4], (bytes4));
+        address a3 = abi.decode(x[4:], (address));
+    }
+}
+
 =====================================output=====================================
 pragma solidity ^0.5.2;
 
@@ -41,5 +49,13 @@ contract Arrays {
     }
 }
 
+contract ArraySlices {
+    function f(bytes calldata x) public {
+        bytes memory a1 = abi.decode(x[:], (bytes));
+        bytes4 a2 = abi.decode(x[:4], (bytes4));
+        address a3 = abi.decode(x[4:], (address));
+    }
+}
+
 ================================================================================
 `;