Implement ES6 transpilation of super.getter calls

[ochafik]

Calls to super getters aren't supported yet.

class Foo {
  get x() { return 'Foo'; }
}
class Bar extends Foo {
  get x() { return super.x; }
}
console.log(new Foo().x);
console.log(new Bar().x);

Current error:

ERROR - ES6 transpilation of 'Only calls to super or to a method of super are supported.' is not yet implemented.
  get x() { return super.x; }
                   ^

This is needed to compile DDC's output with Closure.

[ochafik]

Hey guys, I had a look at how to work around this issue and came up with #1133. Please let me know what you think :-)

[bitbay]

It is still an issue using --language_in ECMASCRIPT6 with --language_out ES5_STRICT.

Closure Compiler (http://github.com/google/closure-compiler)
Version: v20160208
Built on: 2016/02/08 16:23

My workaround using

class Foo {
  set x(value) { this._x = value; }
  setX(value) { this.x = value }
}
class Bar extends Foo {
  set x(value) { super.setX(value); }
}

throws an error:

$ java -jar compiler.jar --language_in ECMASCRIPT6 --language_out ES5_STRICT --compilation_level ADVANCED_OPTIMIZATIONS --js test.js
java.lang.RuntimeException: INTERNAL COMPILER ERROR.                                             
Please report this problem.                                                                      

null                                                                                             
  Node(SUPER): test.js:6:17                                                                      
  set x(value) { super.setX(value); }                                                            
  Parent(GETPROP): test.js:6:17                                                                  
  set x(value) { super.setX(value); }                                                            

        at com.google.javascript.jscomp.Es6ConvertSuper.visitSuper(Es6ConvertSuper.java:137)     
        at com.google.javascript.jscomp.Es6ConvertSuper.visit(Es6ConvertSuper.java:70)           
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:621)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBlockScope(NodeTraversal.java:664) 
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:609)     
        at com.google.javascript.jscomp.NodeTraversal.traverseFunction(NodeTraversal.java:655)   
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:607)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverseBranch(NodeTraversal.java:615)     
        at com.google.javascript.jscomp.NodeTraversal.traverse(NodeTraversal.java:297)           
        at com.google.javascript.jscomp.NodeTraversal.traverseEs6(NodeTraversal.java:564)        
        at com.google.javascript.jscomp.Es6ConvertSuper.process(Es6ConvertSuper.java:191)        
        at com.google.javascript.jscomp.PhaseOptimizer$NamedPass.process(PhaseOptimizer.java:285)
        at com.google.javascript.jscomp.PhaseOptimizer.process(PhaseOptimizer.java:217)          
        at com.google.javascript.jscomp.Compiler.check(Compiler.java:771)                        
        at com.google.javascript.jscomp.Compiler.compileInternal(Compiler.java:687)              
        at com.google.javascript.jscomp.Compiler.access$000(Compiler.java:83)                    
        at com.google.javascript.jscomp.Compiler$2.call(Compiler.java:645)                       
        at com.google.javascript.jscomp.Compiler$2.call(Compiler.java:642)                       
        at com.google.javascript.jscomp.CompilerExecutor$2.call(CompilerExecutor.java:93)        
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)                    
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)                              
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)       
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)       
        at java.lang.Thread.run(Thread.java:722)                                                 
Caused by: java.lang.NullPointerException                                                        
        ... 31 more                                                                              

[ChadKillingsworth]

this was fixed a while ago.