fix: enum as identifier name

src/lexer/tokens.js

@@ -32,6 +32,29 @@ module.exports = {
       }
     }
 
+    // https://github.com/php/php-src/blob/master/Zend/zend_language_scanner.l#L1546
+    if (id === this.tok.T_ENUM) {
+      if (this.version < 801) {
+        return this.tok.T_STRING;
+      }
+      const initial = this.offset;
+      let ch = this.input();
+      while (ch == " ") {
+        ch = this.input();
+      }
+      let isEnum = false;
+      if (this.is_LABEL_START()) {
+        while (this.is_LABEL()) {
+          ch += this.input();
+        }
+        const label = ch.slice(0, -1).toLowerCase();
+        isEnum = label !== "extends" && label !== "implements";
+      }
+
+      this.unput(this.offset - initial);
+      return isEnum ? this.tok.T_ENUM : this.tok.T_STRING;
+    }
+
     if (this.offset < this.size && id !== this.tok.T_YIELD_FROM) {
       // If immediately followed by a backslash, this is a T_NAME_RELATIVE or T_NAME_QUALIFIED.
       let ch = this.input();

test/snapshot/__snapshots__/enum.test.js.snap

@@ -275,8 +275,155 @@ Program {
 }
 `;
 
+exports[`Test enums can't be parsed with PHP < 8 1`] = `"Parse Error : syntax error, unexpected 'Foo' (T_STRING), expecting ';' on line 1"`;
+
 exports[`Test enums cannot have properties 1`] = `"Parse Error : syntax error, unexpected 'int' (T_STRING) on line 3"`;
 
+exports[`Test enums doesn't confuse enums with identifiers 1`] = `
+Program {
+  "children": Array [
+    Class {
+      "attrGroups": Array [],
+      "body": Array [
+        Method {
+          "arguments": Array [],
+          "attrGroups": Array [],
+          "body": Block {
+            "children": Array [],
+            "kind": "block",
+          },
+          "byref": false,
+          "isAbstract": false,
+          "isFinal": false,
+          "isStatic": false,
+          "kind": "method",
+          "name": Identifier {
+            "kind": "identifier",
+            "name": "enum",
+          },
+          "nullable": false,
+          "type": null,
+          "visibility": "",
+        },
+      ],
+      "extends": null,
+      "implements": null,
+      "isAbstract": false,
+      "isAnonymous": false,
+      "isFinal": false,
+      "kind": "class",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    Interface {
+      "attrGroups": Array [],
+      "body": Array [],
+      "extends": null,
+      "kind": "interface",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    Trait {
+      "body": Array [],
+      "kind": "trait",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    _Function {
+      "arguments": Array [],
+      "attrGroups": Array [],
+      "body": Block {
+        "children": Array [],
+        "kind": "block",
+      },
+      "byref": false,
+      "kind": "function",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "enum",
+      },
+      "nullable": false,
+      "type": null,
+    },
+    Class {
+      "attrGroups": Array [],
+      "body": Array [],
+      "extends": Name {
+        "kind": "name",
+        "name": "Foo",
+        "resolution": "uqn",
+      },
+      "implements": null,
+      "isAbstract": false,
+      "isAnonymous": false,
+      "isFinal": false,
+      "kind": "class",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    Class {
+      "attrGroups": Array [],
+      "body": Array [],
+      "extends": null,
+      "implements": Array [
+        Name {
+          "kind": "name",
+          "name": "Foo",
+          "resolution": "uqn",
+        },
+      ],
+      "isAbstract": false,
+      "isAnonymous": false,
+      "isFinal": false,
+      "kind": "class",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    Class {
+      "attrGroups": Array [],
+      "body": Array [],
+      "extends": Name {
+        "kind": "name",
+        "name": "Foo",
+        "resolution": "uqn",
+      },
+      "implements": null,
+      "isAbstract": false,
+      "isAnonymous": false,
+      "isFinal": false,
+      "kind": "class",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "Enum",
+      },
+    },
+    Enum {
+      "attrGroups": Array [],
+      "body": Array [],
+      "implements": null,
+      "kind": "enum",
+      "name": Identifier {
+        "kind": "identifier",
+        "name": "extendsFoo",
+      },
+      "valueType": null,
+    },
+  ],
+  "errors": Array [],
+  "kind": "program",
+}
+`;
+
 exports[`Test enums empty 1`] = `
 Program {
   "children": Array [

test/snapshot/enum.test.js

@@ -90,4 +90,25 @@ describe("Test enums", function () {
       `);
     }).toThrowErrorMatchingSnapshot();
   });
+
+  it("doesn't confuse enums with identifiers", function () {
+    expect(
+      parser.parseEval(`
+      class Enum { function enum () {} }
+      interface Enum {}
+      trait Enum  {}
+      function enum() {}
+      class Enum extends Foo {}
+      class Enum implements Foo {}
+      class Enum exTends Foo {}
+      enum extendsFoo {}
+    `)
+    ).toMatchSnapshot();
+  });
+
+  it("can't be parsed with PHP < 8", function () {
+    expect(() => {
+      parser.parseEval("enum Foo {}", { parser: { version: "8.0" } });
+    }).toThrowErrorMatchingSnapshot();
+  });
 });