Increase test coverage (#175)

* Increase test coverage

* Test for error when binding `this` in destructuring pattern

* Ignore coverage of inAsync check in parseAwait - already checked externally

* Ignore coverage of default case in checkPropClash

* Remove unused parameter isAsync from parseParenAndDistinguishExpression

* Ignore coverage of an `else` branch in flowParseTypeParameterDeclaration

* Flow: remove unused parameters to flowParseTypeAnnotatableIdentifier

* Flow: ignore coverage of pass-through throw statement in parseConditional

* Flow: Add test for error on property with type param

* Flow: ignore coverage of pass-through throw statements in parseMaybeAssign, parseArrow

* Add test for error on XML-style comment in module code

* Update test for error on method in object pattern

* Test for error: "Only '=' operator can be used for specifying default value"

src/parser/expression.js

@@ -45,6 +45,7 @@ pp.checkPropClash = function (prop, propHash) {
       name = String(key.value);
       break;
 
+    // istanbul ignore next: non-computed property keys are always one of the above
     default:
       return;
   }
@@ -555,7 +556,7 @@ pp.parseParenExpression = function () {
   return val;
 };
 
-pp.parseParenAndDistinguishExpression = function (startPos, startLoc, canBeArrow, isAsync) {
+pp.parseParenAndDistinguishExpression = function (startPos, startLoc, canBeArrow) {
   startPos = startPos || this.state.start;
   startLoc = startLoc || this.state.startLoc;
 
@@ -597,15 +598,11 @@ pp.parseParenAndDistinguishExpression = function (startPos, startLoc, canBeArrow
       if (param.extra && param.extra.parenthesized) this.unexpected(param.extra.parenStart);
     }
 
-    return this.parseArrowExpression(arrowNode, exprList, isAsync);
+    return this.parseArrowExpression(arrowNode, exprList);
   }
 
   if (!exprList.length) {
-    if (isAsync) {
-      return;
-    } else {
-      this.unexpected(this.state.lastTokStart);
-    }
+    this.unexpected(this.state.lastTokStart);
   }
   if (optionalCommaStart) this.unexpected(optionalCommaStart);
   if (spreadStart) this.unexpected(spreadStart);
@@ -1025,6 +1022,7 @@ pp.parseIdentifier = function (liberal) {
 // Parses await expression inside async function.
 
 pp.parseAwait = function (node) {
+  // istanbul ignore next: this condition is checked at the call site so won't be hit here
   if (!this.state.inAsync) {
     this.unexpected();
   }

src/parser/statement.js

@@ -670,7 +670,6 @@ pp.parseClassBody = function (node) {
 
     method.static = isMaybeStatic && !this.match(tt.parenL);
     if (method.static) {
-      if (isGenerator) this.unexpected();
       isGenerator = this.eat(tt.star);
       this.parsePropertyName(method);
     }

src/plugins/flow.js

@@ -207,7 +207,7 @@ pp.flowParseTypeParameter = function () {
 
   let variance = this.flowParseVariance();
 
-  let ident = this.flowParseTypeAnnotatableIdentifier(false, false);
+  let ident = this.flowParseTypeAnnotatableIdentifier();
   node.name = ident.name;
   node.variance = variance;
   node.bound = ident.typeAnnotation;
@@ -227,6 +227,7 @@ pp.flowParseTypeParameterDeclaration = function () {
 
   this.state.inType = true;
 
+  // istanbul ignore else: this condition is already checked at all call sites
   if (this.isRelational("<") || this.match(tt.jsxTagStart)) {
     this.next();
   } else {
@@ -705,26 +706,12 @@ pp.flowParseTypeAnnotation = function () {
   return this.finishNode(node, "TypeAnnotation");
 };
 
-pp.flowParseTypeAnnotatableIdentifier = function (requireTypeAnnotation, canBeOptionalParam) {
-
+pp.flowParseTypeAnnotatableIdentifier = function () {
   let ident = this.parseIdentifier();
-  let isOptionalParam = false;
-
-  if (canBeOptionalParam && this.eat(tt.question)) {
-    this.expect(tt.question);
-    isOptionalParam = true;
-  }
-
-  if (requireTypeAnnotation || this.match(tt.colon)) {
+  if (this.match(tt.colon)) {
     ident.typeAnnotation = this.flowParseTypeAnnotation();
     this.finishNode(ident, ident.type);
   }
-
-  if (isOptionalParam) {
-    ident.optional = true;
-    this.finishNode(ident, ident.type);
-  }
-
   return ident;
 };
 
@@ -824,6 +811,7 @@ export default function (instance) {
             refNeedsArrowPos.start = err.pos || this.state.start;
             return expr;
           } else {
+            // istanbul ignore next: no such error is expected
             throw err;
           }
         }
@@ -1208,6 +1196,7 @@ export default function (instance) {
             this.state = state;
             jsxError = err;
           } else {
+            // istanbul ignore next: no such error is expected
             throw err;
           }
         }
@@ -1262,6 +1251,7 @@ export default function (instance) {
           if (err instanceof SyntaxError) {
             this.state = state;
           } else {
+            // istanbul ignore next: no such error is expected
             throw err;
           }
         }

src/plugins/jsx/index.js

@@ -365,6 +365,7 @@ pp.jsxParseElementAt = function(startPos, startLoc) {
 
           break;
 
+        // istanbul ignore next - should never happen
         default:
           this.unexpected();
       }

test/fixtures/core/categorized/label-kind-switch/actual.js

@@ -0,0 +1,4 @@
+{
+  a: switch (i) {
+  }
+}

test/fixtures/core/categorized/label-kind-switch/expected.json

@@ -0,0 +1,117 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 25,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 4,
+      "column": 1
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 25,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 4,
+        "column": 1
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "BlockStatement",
+        "start": 0,
+        "end": 25,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 4,
+            "column": 1
+          }
+        },
+        "body": [
+          {
+            "type": "LabeledStatement",
+            "start": 4,
+            "end": 23,
+            "loc": {
+              "start": {
+                "line": 2,
+                "column": 2
+              },
+              "end": {
+                "line": 3,
+                "column": 3
+              }
+            },
+            "body": {
+              "type": "SwitchStatement",
+              "start": 7,
+              "end": 23,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 5
+                },
+                "end": {
+                  "line": 3,
+                  "column": 3
+                }
+              },
+              "discriminant": {
+                "type": "Identifier",
+                "start": 15,
+                "end": 16,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 13
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 14
+                  },
+                  "identifierName": "i"
+                },
+                "name": "i"
+              },
+              "cases": []
+            },
+            "label": {
+              "type": "Identifier",
+              "start": 4,
+              "end": 5,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 2
+                },
+                "end": {
+                  "line": 2,
+                  "column": 3
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            }
+          }
+        ],
+        "directives": []
+      }
+    ],
+    "directives": []
+  }
+}

test/fixtures/core/categorized/malformed-switch/actual.js

@@ -0,0 +1,3 @@
+switch (x) {
+  var y = 5;
+}

test/fixtures/core/categorized/malformed-switch/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:2)"
+}

test/fixtures/es2015/class-methods/direct-super-outside-constructor/actual.js

@@ -0,0 +1,3 @@
+class A {
+  x () {super()}
+}

test/fixtures/es2015/class-methods/direct-super-outside-constructor/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "super() outside of class constructor (2:8)"
+}

test/fixtures/es2015/class-methods/disallow-static-prototype/actual.js

@@ -0,0 +1,3 @@
+class A {
+  static prototype() {}
+}

test/fixtures/es2015/class-methods/disallow-static-prototype/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Classes may not have static property named prototype (2:9)"
+}

test/fixtures/es2015/class-methods/getter-signature/actual.js

@@ -0,0 +1,3 @@
+class A {
+  get prop (arg) {}
+}

test/fixtures/es2015/class-methods/getter-signature/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "getter should have no params (2:2)"
+}

test/fixtures/es2015/class-methods/malformed-super-expression/actual.js

@@ -0,0 +1,5 @@
+class A {
+  x () {
+    super - 1;
+  }
+}

test/fixtures/es2015/class-methods/malformed-super-expression/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (3:10)"
+}

test/fixtures/es2015/destructuring/binding-this/actual.js

@@ -0,0 +1 @@
+var { this };

test/fixtures/es2015/destructuring/binding-this/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Binding this (1:6)"
+}

test/fixtures/es2015/destructuring/error-operator-for-default/actual.js

@@ -0,0 +1 @@
+([a += a] = a)

test/fixtures/es2015/destructuring/error-operator-for-default/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Only '=' operator can be used for specifying default value. (1:3)"
+}

test/fixtures/es2015/modules/xml-comment-in-module/actual.js

@@ -0,0 +1 @@
+foo <!--bar

test/fixtures/es2015/modules/xml-comment-in-module/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (1:4)"
+}

test/fixtures/es2017/async-functions/no-constructor/actual.js

@@ -0,0 +1,3 @@
+class A {
+  async constructor() {}
+}

test/fixtures/es2017/async-functions/no-constructor/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Constructor can't be an async function (2:8)"
+}

test/fixtures/esprima/es2015-destructuring-assignment-object-pattern/invalid-pattern-with-method/actual.js

@@ -1 +1 @@
-({get a(){}})=0
+({a(){}})=0

test/fixtures/esprima/es2015-destructuring-assignment-object-pattern/invalid-pattern-with-method/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Object pattern can't contain getter or setter (1:6)"
-}
+  "throws": "Object pattern can't contain methods (1:2)"
+}

test/fixtures/experimental/no-async-generators/error-without-plugin/actual.js

@@ -0,0 +1 @@
+async function * f () {}

test/fixtures/experimental/no-async-generators/error-without-plugin/options.json

@@ -0,0 +1,4 @@
+{
+  "throws": "Unexpected token (1:15)",
+  "plugins": []
+}

test/fixtures/flow/type-parameter-declaration/error-object-property-type-param/actual.js

@@ -0,0 +1,3 @@
+const s = {
+  p<T>
+}

test/fixtures/flow/type-parameter-declaration/error-object-property-type-param/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (3:0)"
+}

test/fixtures/jsx/basic/entity/actual.js

@@ -0,0 +1 @@
+<A>&#x1f4a9;</A>