Handle let expressions without values (#316)

Author: fvictorio

src/nodes/AssemblyLocalDefinition.js

@@ -7,13 +7,19 @@ const {
 const printSeparatedList = require('./print-separated-list');
 
 const AssemblyLocalDefinition = {
-  print: ({ path, print }) =>
-    concat([
+  print: ({ node, path, print }) => {
+    const parts = [
       'let',
-      printSeparatedList(path.map(print, 'names'), { firstSeparator: line }),
-      ':= ',
-      path.call(print, 'expression')
-    ])
+      printSeparatedList(path.map(print, 'names'), { firstSeparator: line })
+    ];
+
+    if (node.expression !== null) {
+      parts.push(':= ');
+      parts.push(path.call(print, 'expression'));
+    }
+
+    return concat(parts);
+  }
 };
 
 module.exports = AssemblyLocalDefinition;

tests/Assembly/Assembly.sol

@@ -147,4 +147,9 @@ function $somefn(somearg) {
 }
     }
   }
+
+    function   letWithoutValue ( ) {
+
+       assembly {   let result   }
+  }
 }

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

@@ -150,6 +150,11 @@ function $somefn(somearg) {
 }
     }
   }
+
+    function   letWithoutValue ( ) {
+
+       assembly {   let result   }
+  }
 }
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 contract Assembly {
@@ -336,6 +341,12 @@ contract Assembly {
             }
         }
     }
+
+    function letWithoutValue() {
+        assembly {
+            let result
+        }
+    }
 }
 
 `;