change some things to expectPlugin

src/parser/expression.js

@@ -433,12 +433,7 @@ export default class ExpressionParser extends LValParser {
         noCalls,
       );
     } else if (this.match(tt.questionDot)) {
-      if (!this.hasPlugin("optionalChaining")) {
-        this.raise(
-          startPos,
-          "You can only use optional-chaining when the 'optionalChaining' plugin is enabled.",
-        );
-      }
+      this.expectPlugin("optionalChaining");
 
       if (noCalls && this.lookahead().type == tt.parenL) {
         state.stop = true;
@@ -660,11 +655,11 @@ export default class ExpressionParser extends LValParser {
         return this.finishNode(node, "Super");
 
       case tt._import:
-        if (this.hasPlugin("importMeta") && this.lookahead().type === tt.dot) {
+        if (this.lookahead().type === tt.dot) {
           return this.parseImportMetaProperty();
         }
 
-        if (!this.hasPlugin("dynamicImport")) this.unexpected();
+        this.expectPlugin("dynamicImport");
 
         node = this.startNode();
         this.next();
@@ -712,7 +707,9 @@ export default class ExpressionParser extends LValParser {
         return id;
 
       case tt._do:
-        if (this.hasPlugin("doExpressions")) {
+        // TODO
+        if (true) {
+          this.expectPlugin("doExpressions");
           const node = this.startNode();
           this.next();
           const oldInFunction = this.state.inFunction;
@@ -825,11 +822,7 @@ export default class ExpressionParser extends LValParser {
   parseFunctionExpression(): N.FunctionExpression | N.MetaProperty {
     const node = this.startNode();
     const meta = this.parseIdentifier(true);
-    if (
-      this.state.inGenerator &&
-      this.hasPlugin("functionSent") &&
-      this.eat(tt.dot)
-    ) {
+    if (this.state.inGenerator && this.eat(tt.dot)) {
       return this.parseMetaProperty(node, meta, "sent");
     }
     return this.parseFunction(node, false);
@@ -841,6 +834,16 @@ export default class ExpressionParser extends LValParser {
     propertyName: string,
   ): N.MetaProperty {
     node.meta = meta;
+
+    if (meta.name === "function" && propertyName === "sent") {
+      if (this.isContextual(propertyName)) {
+        this.expectPlugin("functionSent");
+      } else if (!this.hasPlugin("functionSent")) {
+        // They didn't actually say `function.sent`, just `function.`, so a simple error would be less confusing.
+        this.unexpected();
+      }
+    }
+
     node.property = this.parseIdentifier(true);
 
     if (node.property.name !== propertyName) {
@@ -857,6 +860,18 @@ export default class ExpressionParser extends LValParser {
     const node = this.startNode();
     const id = this.parseIdentifier(true);
     this.expect(tt.dot);
+
+    if (id.name === "import") {
+      if (this.isContextual("meta")) {
+        this.expectPlugin("importMeta");
+      } else if (!this.hasPlugin("importMeta")) {
+        this.raise(
+          null,
+          `Dynamic imports require a parameter: import('a.js').then`,
+        );
+      }
+    }
+
     if (!this.inModule) {
       this.raise(
         id.start,
@@ -1141,7 +1156,8 @@ export default class ExpressionParser extends LValParser {
         decorators = [];
       }
 
-      if (this.hasPlugin("objectRestSpread") && this.match(tt.ellipsis)) {
+      if (this.match(tt.ellipsis)) {
+        this.expectPlugin("objectRestSpread");
         prop = this.parseSpread(isPattern ? { start: 0 } : undefined);
         if (isPattern) {
           this.toAssignable(prop, true, "object pattern");
@@ -1199,8 +1215,11 @@ export default class ExpressionParser extends LValParser {
           prop.computed = false;
         } else {
           isAsync = true;
-          if (this.hasPlugin("asyncGenerators"))
-            isGenerator = this.eat(tt.star);
+          if (this.match(tt.star)) {
+            this.expectPlugin("asyncGenerators");
+            this.next();
+            isGenerator = true;
+          }
           this.parsePropertyName(prop);
         }
       } else {

src/parser/location.js

@@ -10,7 +10,11 @@ import CommentsParser from "./comments";
 // message.
 
 export default class LocationParser extends CommentsParser {
-  raise(pos: number, message: string, missingPluginName: string): empty {
+  raise(
+    pos: number,
+    message: string,
+    missingPluginNames?: Array<string>,
+  ): empty {
     const loc = getLineInfo(this.input, pos);
     message += ` (${loc.line}:${loc.column})`;
     // $FlowIgnore
@@ -19,8 +23,8 @@ export default class LocationParser extends CommentsParser {
     );
     err.pos = pos;
     err.loc = loc;
-    if (missingPluginName) {
-      err.missingPlugin = missingPluginName;
+    if (missingPluginNames) {
+      err.missingPlugin = missingPluginNames;
     }
     throw err;
   }

src/parser/statement.js

@@ -237,9 +237,7 @@ export default class StatementParser extends ExpressionParser {
   }
 
   parseDecorator(): N.Decorator {
-    if (!(this.hasPlugin("decorators") || this.hasPlugin("decorators2"))) {
-      this.unexpected();
-    }
+    this.expectOnePlugin(["decorators", "decorators2"]);
 
     const node = this.startNode();
     this.next();
@@ -340,11 +338,8 @@ export default class StatementParser extends ExpressionParser {
     this.state.labels.push(loopLabel);
 
     let forAwait = false;
-    if (
-      this.hasPlugin("asyncGenerators") &&
-      this.state.inAsync &&
-      this.isContextual("await")
-    ) {
+    if (this.state.inAsync && this.isContextual("await")) {
+      this.expectPlugin("asyncGenerators");
       forAwait = true;
       this.next();
     }
@@ -489,12 +484,13 @@ export default class StatementParser extends ExpressionParser {
     if (this.match(tt._catch)) {
       const clause = this.startNode();
       this.next();
-      if (this.match(tt.parenL) || !this.hasPlugin("optionalCatchBinding")) {
+      if (this.match(tt.parenL)) {
         this.expect(tt.parenL);
         clause.param = this.parseBindingAtom();
         this.checkLVal(clause.param, true, Object.create(null), "catch clause");
         this.expect(tt.parenR);
       } else {
+        this.expectPlugin("optionalCatchBinding");
         clause.param = null;
       }
       clause.body = this.parseBlock();
@@ -782,12 +778,11 @@ export default class StatementParser extends ExpressionParser {
     this.initFunction(node, isAsync);
 
     if (this.match(tt.star)) {
-      if (node.async && !this.hasPlugin("asyncGenerators")) {
-        this.unexpected();
-      } else {
-        node.generator = true;
-        this.next();
+      if (node.async) {
+        this.expectPlugin("asyncGenerators");
       }
+      node.generator = true;
+      this.next();
     }
 
     if (
@@ -960,8 +955,9 @@ export default class StatementParser extends ExpressionParser {
       isStatic = true;
     }
 
-    if (this.hasPlugin("classPrivateProperties") && this.match(tt.hash)) {
+    if (this.match(tt.hash)) {
       // Private property
+      this.expectPlugin("classPrivateProperties");
       this.next();
       const privateProp: N.ClassPrivateProperty = memberAny;
       privateProp.key = this.parseIdentifier(true);
@@ -1047,8 +1043,12 @@ export default class StatementParser extends ExpressionParser {
       this.pushClassProperty(classBody, prop);
     } else if (isSimple && key.name === "async" && !this.isLineTerminator()) {
       // an async method
-      const isGenerator =
-        this.hasPlugin("asyncGenerators") && this.eat(tt.star);
+      let isGenerator = false;
+      if (this.match(tt.star)) {
+        this.expectPlugin("asyncGenerators");
+        this.next();
+        isGenerator = true;
+      }
       method.kind = "method";
       this.parsePropertyName(method);
       if (this.isNonstaticConstructor(method)) {

src/parser/util.js

@@ -114,8 +114,20 @@ export default class UtilParser extends Tokenizer {
     if (!this.hasPlugin(name)) {
       throw this.raise(
         this.state.start,
-        `This experimental syntax requires enabling the parser plugin: ${name}`,
-        name,
+        `This experimental syntax requires enabling the parser plugin: '${name}'`,
+        [name],
+      );
+    }
+  }
+
+  expectOnePlugin(names: Array<string>): void {
+    if (!names.some(n => this.hasPlugin(n))) {
+      throw this.raise(
+        this.state.start,
+        `This experimental syntax requires enabling the parser plugin(s): '${names.join(
+          ", ",
+        )}'`,
+        names,
       );
     }
   }

test/fixtures/experimental/dynamic-import/direct-calls-only/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (2:15)"
+  "throws": "Dynamic imports require a parameter: import('a.js').then (1:0)"
 }

test/fixtures/experimental/function-sent/disabled-function-keyword-declaration/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (2:10)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'functionSent' (2:11)"
 }

test/fixtures/experimental/function-sent/disabled-function-keyword-expression/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (2:11)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'functionSent' (2:12)"
 }

test/fixtures/experimental/function-sent/disabled-inside-generator/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (2:17)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'functionSent' (2:18)"
 }

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

@@ -1,4 +1,4 @@
 {
-  "throws": "Unexpected token (1:15)",
+  "throws": "This experimental syntax requires enabling the parser plugin: 'asyncGenerators' (1:15)",
   "plugins": []
-}
+}

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

@@ -0,0 +1,2 @@
+@memoize
+function() {}

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

@@ -0,0 +1,4 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin(s): 'decorators, decorators2' (1:0)",
+  "plugins": []
+}

test/fixtures/experimental/no-do-expressions/error-without-plugin/actual.js

@@ -0,0 +1 @@
+(do {x})

test/fixtures/experimental/no-do-expressions/error-without-plugin/options.json

@@ -0,0 +1,4 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin: 'doExpressions' (1:1)",
+  "plugins": []
+}

test/fixtures/experimental/no-dynamic-import/error-without-plugin/actual.js

@@ -0,0 +1 @@
+var $ = import("jquery");

test/fixtures/experimental/no-dynamic-import/error-without-plugin/options.json

@@ -0,0 +1,4 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin: 'dynamicImport' (1:8)",
+  "plugins": []
+}

test/fixtures/experimental/no-import-meta/error-without-plugin/actual.js

@@ -0,0 +1 @@
+const x = import.meta;

test/fixtures/experimental/no-import-meta/error-without-plugin/options.json

@@ -0,0 +1,5 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin: 'importMeta' (1:17)",
+  "sourceType": "module",
+  "plugins": []
+}

test/fixtures/experimental/no-object-rest-spread/error-without-plugin/actual.js

@@ -0,0 +1 @@
+({...x})

test/fixtures/experimental/no-object-rest-spread/error-without-plugin/options.json

@@ -0,0 +1,4 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin: 'objectRestSpread' (1:2)",
+  "plugins": []
+}

test/fixtures/experimental/optional-catch-binding/no-plugin-no-binding-finally/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (4:6)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'optionalCatchBinding' (4:6)"
 }

test/fixtures/experimental/optional-catch-binding/no-plugin-no-binding/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Unexpected token, expected ( (4:6)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'optionalCatchBinding' (4:6)"
 }

test/fixtures/experimental/optional-chaining/missing-plugin/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "You can only use optional-chaining when the 'optionalChaining' plugin is enabled. (1:0)"
+  "throws": "This experimental syntax requires enabling the parser plugin: 'optionalChaining' (1:1)"
 }