[[FIX]] Disallow YieldExpression in gnrtr params

src/jshint.js

@@ -3645,6 +3645,7 @@ var JSHINT = (function() {
       state.funct["(metrics)"].arity = paramsInfo.arity;
       state.funct["(metrics)"].verifyMaxParametersPerFunction();
     } else {
+      state.funct["(params)"] = [];
       state.funct["(metrics)"].arity = 0;
       state.funct["(hasSimpleParams)"] = true;
     }
@@ -3803,7 +3804,7 @@ var JSHINT = (function() {
 //object literals
   (function(x) {
     x.nud = function(context) {
-      var b, f, i, p, t, isGeneratorMethod = false, nextVal;
+      var b, f, i, params, t, isGeneratorMethod = false, nextVal;
       var props = Object.create(null); // All properties, including accessors
 
       b = state.tokens.curr.line !== startLine(state.tokens.next);
@@ -3867,11 +3868,11 @@ var JSHINT = (function() {
 
           t = state.tokens.next;
           f = doFunction(context, { isMethod: true });
-          p = f["(params)"];
+          params = f["(params)"];
 
           // Don't warn about getter/setter pairs if this is an ES6 concise method
-          if (nextVal === "get" && i && p) {
-            warning("W076", t, p[0], i);
+          if (nextVal === "get" && i && params.length) {
+            warning("W076", t, params[0], i);
           } else if (nextVal === "set" && i && f["(metrics)"].arity !== 1) {
             warning("W077", t, i);
           }
@@ -5105,6 +5106,13 @@ var JSHINT = (function() {
     }
     var prev = state.tokens.prev;
 
+    // If the parameters of the current function scope have not been defined,
+    // it is because the current expression is contained within the parameter
+    // list.
+    if (!state.funct["(params)"]) {
+      error("E024", this, "yield");
+    }
+
     if (!this.beginsStmt && prev.lbp > 30 && !checkPunctuators(prev, ["("])) {
       error("E061", this);
     }

tests/test262/expectations.txt

@@ -516,8 +516,6 @@ test/language/expressions/template-literal/tv-utf16-escape-sequence.js(strict mo
 test/language/expressions/function/param-dflt-yield-non-strict.js(default)
 test/language/expressions/function/scope-param-rest-elem-var-close.js(default)
 test/language/expressions/function/scope-param-rest-elem-var-open.js(default)
-test/language/expressions/generators/param-dflt-yield.js(default)
-test/language/expressions/generators/param-dflt-yield.js(strict mode)
 test/language/expressions/generators/scope-param-rest-elem-var-close.js(default)
 test/language/expressions/generators/scope-param-rest-elem-var-open.js(default)
 test/language/expressions/generators/yield-as-function-expression-binding-identifier.js(default)
@@ -526,12 +524,8 @@ test/language/expressions/generators/yield-as-logical-or-expression.js(default)
 test/language/expressions/generators/yield-as-logical-or-expression.js(strict mode)
 test/language/expressions/generators/yield-star-after-newline.js(default)
 test/language/expressions/generators/yield-star-after-newline.js(strict mode)
-test/language/expressions/class/gen-method-param-dflt-yield.js(default)
-test/language/expressions/class/gen-method-param-dflt-yield.js(strict mode)
 test/language/expressions/class/getter-param-dflt.js(default)
 test/language/expressions/class/getter-param-dflt.js(strict mode)
-test/language/expressions/class/static-gen-method-param-dflt-yield.js(default)
-test/language/expressions/class/static-gen-method-param-dflt-yield.js(strict mode)
 test/language/expressions/assignment/dstr-array-elem-init-simple-no-strict.js(default)
 test/language/expressions/assignment/dstr-array-elem-init-yield-ident-valid.js(default)
 test/language/expressions/assignment/dstr-array-elem-iter-rtrn-close-err.js(default)
@@ -613,7 +607,6 @@ test/language/expressions/object/method-definition/async-super-call-body.js(defa
 test/language/expressions/object/method-definition/async-super-call-body.js(strict mode)
 test/language/expressions/object/method-definition/async-super-call-param.js(default)
 test/language/expressions/object/method-definition/async-super-call-param.js(strict mode)
-test/language/expressions/object/method-definition/generator-param-init-yield.js(default)
 test/language/expressions/object/method-definition/generator-prop-name-yield-expr.js(default)
 test/language/expressions/object/method-definition/generator-prop-name-yield-id.js(default)
 test/language/expressions/object/method-definition/name-param-id-yield.js(default)
@@ -708,8 +701,6 @@ test/language/statements/if/if-stmt-else-decl-strict.js(strict mode)
 test/language/statements/if/if-stmt-else-fun-strict.js(strict mode)
 test/language/statements/if/if-stmt-else-gen.js(default)
 test/language/statements/if/if-stmt-else-gen.js(strict mode)
-test/language/statements/generators/param-dflt-yield.js(default)
-test/language/statements/generators/param-dflt-yield.js(strict mode)
 test/language/statements/generators/scope-param-rest-elem-var-close.js(default)
 test/language/statements/generators/scope-param-rest-elem-var-open.js(default)
 test/language/statements/generators/yield-as-function-expression-binding-identifier.js(default)
@@ -872,12 +863,8 @@ test/language/statements/let/syntax/with-initialisers-in-statement-positions-lab
 test/language/statements/let/syntax/with-initialisers-in-statement-positions-label-statement.js(strict mode)
 test/language/statements/let/syntax/without-initialisers-in-statement-positions-label-statement.js(default)
 test/language/statements/let/syntax/without-initialisers-in-statement-positions-label-statement.js(strict mode)
-test/language/statements/class/gen-method-param-dflt-yield.js(default)
-test/language/statements/class/gen-method-param-dflt-yield.js(strict mode)
 test/language/statements/class/getter-param-dflt.js(default)
 test/language/statements/class/getter-param-dflt.js(strict mode)
-test/language/statements/class/static-gen-method-param-dflt-yield.js(default)
-test/language/statements/class/static-gen-method-param-dflt-yield.js(strict mode)
 test/language/statements/class/definition/class-method-returns-promise.js(default)
 test/language/statements/class/definition/class-method-returns-promise.js(strict mode)
 test/language/statements/class/definition/methods-async-super-call-body.js(default)

tests/unit/parser.js

@@ -3781,6 +3781,18 @@ exports["esnext generator"] = function (test) {
   TestRun(test)
     .test(code, {esnext: true, unused: true, undef: true, predef: ["print"]});
 
+  TestRun(test, "YieldExpression in parameters - declaration")
+    .addError(1, 18, "Unexpected 'yield'.")
+    .test("function * g(x = yield) { yield; }", { esversion: 6 });
+
+  TestRun(test, "YieldExpression in parameters - expression")
+    .addError(1, 22, "Unexpected 'yield'.")
+    .test("void function * (x = yield) { yield; };", { esversion: 6 });
+
+  TestRun(test, "YieldExpression in parameters - method")
+    .addError(1, 16, "Unexpected 'yield'.")
+    .test("void { * g(x = yield) { yield; } };", { esversion: 6 });
+
   test.done();
 };