Further refactoring of @babel/eslint-parser (#11071)

eslint/babel-eslint-parser/src/analyze-scope.js

@@ -318,7 +318,7 @@ class Referencer extends OriginalReferencer {
   }
 }
 
-export default function(ast, parserOptions) {
+export default function analyzeScope(ast, parserOptions) {
   const options = {
     ignoreEval: true,
     optimistic: false,

eslint/babel-eslint-parser/src/babylon-to-espree/convertAST.js

@@ -1,96 +0,0 @@
-import { types as t, traverse } from "@babel/core";
-import convertProgramNode from "./convertProgramNode";
-
-const astTransformVisitor = {
-  noScope: true,
-  enter(path) {
-    const node = path.node;
-
-    // private var to track original node type
-    node._babelType = node.type;
-
-    if (node.innerComments) {
-      delete node.innerComments;
-    }
-
-    if (node.trailingComments) {
-      delete node.trailingComments;
-    }
-
-    if (node.leadingComments) {
-      delete node.leadingComments;
-    }
-  },
-  exit(path) {
-    const node = path.node;
-
-    if (path.isTypeParameter()) {
-      node.type = "Identifier";
-      node.typeAnnotation = node.bound;
-      delete node.bound;
-    }
-
-    // flow: prevent "no-undef"
-    // for "Component" in: "let x: React.Component"
-    if (path.isQualifiedTypeIdentifier()) {
-      delete node.id;
-    }
-    // for "b" in: "var a: { b: Foo }"
-    if (path.isObjectTypeProperty()) {
-      delete node.key;
-    }
-    // for "indexer" in: "var a: {[indexer: string]: number}"
-    if (path.isObjectTypeIndexer()) {
-      delete node.id;
-    }
-    // for "param" in: "var a: { func(param: Foo): Bar };"
-    if (path.isFunctionTypeParam()) {
-      delete node.name;
-    }
-
-    // modules
-    if (path.isImportDeclaration()) {
-      delete node.isType;
-    }
-
-    // template string range fixes
-    if (path.isTemplateLiteral()) {
-      for (let i = 0; i < node.quasis.length; i++) {
-        const q = node.quasis[i];
-        q.range[0] -= 1;
-        if (q.tail) {
-          q.range[1] += 1;
-        } else {
-          q.range[1] += 2;
-        }
-        q.loc.start.column -= 1;
-        if (q.tail) {
-          q.loc.end.column += 1;
-        } else {
-          q.loc.end.column += 2;
-        }
-      }
-    }
-  },
-};
-
-export default function(ast, code) {
-  const state = { source: code };
-
-  // Monkey patch visitor keys in order to be able to traverse the estree nodes
-  t.VISITOR_KEYS.Property = t.VISITOR_KEYS.ObjectProperty;
-  t.VISITOR_KEYS.MethodDefinition = [
-    "key",
-    "value",
-    "decorators",
-    "returnType",
-    "typeParameters",
-  ];
-
-  traverse(ast, astTransformVisitor, null, state);
-
-  delete t.VISITOR_KEYS.Property;
-  delete t.VISITOR_KEYS.MethodDefinition;
-
-  convertProgramNode(ast);
-}

eslint/babel-eslint-parser/src/babylon-to-espree/convertProgramNode.js

@@ -1,38 +0,0 @@
-export default function(ast) {
-  ast.type = "Program";
-  ast.sourceType = ast.program.sourceType;
-  ast.directives = ast.program.directives;
-  ast.body = ast.program.body;
-  delete ast.program;
-
-  if (ast.comments.length) {
-    const lastComment = ast.comments[ast.comments.length - 1];
-
-    if (!ast.tokens.length) {
-      // if no tokens, the program starts at the end of the last comment
-      ast.start = lastComment.end;
-      ast.loc.start.line = lastComment.loc.end.line;
-      ast.loc.start.column = lastComment.loc.end.column;
-    } else {
-      const lastToken = ast.tokens[ast.tokens.length - 1];
-
-      if (lastComment.end > lastToken.end) {
-        // If there is a comment after the last token, the program ends at the
-        // last token and not the comment
-        ast.range[1] = lastToken.end;
-        ast.loc.end.line = lastToken.loc.end.line;
-        ast.loc.end.column = lastToken.loc.end.column;
-      }
-    }
-  } else {
-    if (!ast.tokens.length) {
-      ast.loc.start.line = 1;
-      ast.loc.end.line = 1;
-    }
-  }
-
-  if (ast.body && ast.body.length > 0) {
-    ast.loc.start.line = ast.body[0].loc.start.line;
-    ast.range[0] = ast.body[0].start;
-  }
-}

eslint/babel-eslint-parser/src/babylon-to-espree/convertTemplateType.js

@@ -1,92 +0,0 @@
-import { tokTypes as tt } from "@babel/core";
-
-export default function(tokens) {
-  let curlyBrace = null;
-  let templateTokens = [];
-  const result = [];
-
-  function addTemplateType() {
-    const start = templateTokens[0];
-    const end = templateTokens[templateTokens.length - 1];
-
-    const value = templateTokens.reduce((result, token) => {
-      if (token.value) {
-        result += token.value;
-      } else if (token.type !== tt.template) {
-        result += token.type.label;
-      }
-
-      return result;
-    }, "");
-
-    result.push({
-      type: "Template",
-      value: value,
-      start: start.start,
-      end: end.end,
-      loc: {
-        start: start.loc.start,
-        end: end.loc.end,
-      },
-    });
-
-    templateTokens = [];
-  }
-
-  tokens.forEach(token => {
-    switch (token.type) {
-      case tt.backQuote:
-        if (curlyBrace) {
-          result.push(curlyBrace);
-          curlyBrace = null;
-        }
-
-        templateTokens.push(token);
-
-        if (templateTokens.length > 1) {
-          addTemplateType();
-        }
-
-        break;
-
-      case tt.dollarBraceL:
-        templateTokens.push(token);
-        addTemplateType();
-        break;
-
-      case tt.braceR:
-        if (curlyBrace) {
-          result.push(curlyBrace);
-        }
-
-        curlyBrace = token;
-        break;
-
-      case tt.template:
-        if (curlyBrace) {
-          templateTokens.push(curlyBrace);
-          curlyBrace = null;
-        }
-
-        templateTokens.push(token);
-        break;
-
-      case tt.eof:
-        if (curlyBrace) {
-          result.push(curlyBrace);
-        }
-
-        break;
-
-      default:
-        if (curlyBrace) {
-          result.push(curlyBrace);
-          curlyBrace = null;
-        }
-
-        result.push(token);
-    }
-  });
-
-  return result;
-}

eslint/babel-eslint-parser/src/babylon-to-espree/convertTokens.js

@@ -1,8 +0,0 @@
-import convertTemplateType from "./convertTemplateType";
-import convertToken from "./convertToken";
-
-export default function(tokens, code) {
-  return convertTemplateType(tokens)
-    .filter(t => t.type !== "CommentLine" && t.type !== "CommentBlock")
-    .map(t => convertToken(t, code));
-}

eslint/babel-eslint-parser/src/convert/convertAST.js

@@ -0,0 +1,137 @@
+import { types as t, traverse } from "@babel/core";
+
+function convertNodes(ast, code) {
+  const state = { source: code };
+  const astTransformVisitor = {
+    noScope: true,
+    enter(path) {
+      const node = path.node;
+
+      // private var to track original node type
+      node._babelType = node.type;
+
+      if (node.innerComments) {
+        delete node.innerComments;
+      }
+
+      if (node.trailingComments) {
+        delete node.trailingComments;
+      }
+
+      if (node.leadingComments) {
+        delete node.leadingComments;
+      }
+    },
+    exit(path) {
+      const node = path.node;
+
+      if (path.isTypeParameter()) {
+        node.type = "Identifier";
+        node.typeAnnotation = node.bound;
+        delete node.bound;
+      }
+
+      // flow: prevent "no-undef"
+      // for "Component" in: "let x: React.Component"
+      if (path.isQualifiedTypeIdentifier()) {
+        delete node.id;
+      }
+      // for "b" in: "var a: { b: Foo }"
+      if (path.isObjectTypeProperty()) {
+        delete node.key;
+      }
+      // for "indexer" in: "var a: {[indexer: string]: number}"
+      if (path.isObjectTypeIndexer()) {
+        delete node.id;
+      }
+      // for "param" in: "var a: { func(param: Foo): Bar };"
+      if (path.isFunctionTypeParam()) {
+        delete node.name;
+      }
+
+      // modules
+      if (path.isImportDeclaration()) {
+        delete node.isType;
+      }
+
+      // template string range fixes
+      if (path.isTemplateLiteral()) {
+        for (let i = 0; i < node.quasis.length; i++) {
+          const q = node.quasis[i];
+          q.range[0] -= 1;
+          if (q.tail) {
+            q.range[1] += 1;
+          } else {
+            q.range[1] += 2;
+          }
+          q.loc.start.column -= 1;
+          if (q.tail) {
+            q.loc.end.column += 1;
+          } else {
+            q.loc.end.column += 2;
+          }
+        }
+      }
+    },
+  };
+
+  // Monkey patch visitor keys in order to be able to traverse the estree nodes
+  t.VISITOR_KEYS.Property = t.VISITOR_KEYS.ObjectProperty;
+  t.VISITOR_KEYS.MethodDefinition = [
+    "key",
+    "value",
+    "decorators",
+    "returnType",
+    "typeParameters",
+  ];
+
+  traverse(ast, astTransformVisitor, null, state);
+
+  // These can be safely deleted because they are not defined in the original visitor keys.
+  delete t.VISITOR_KEYS.Property;
+  delete t.VISITOR_KEYS.MethodDefinition;
+}
+
+function convertProgramNode(ast) {
+  ast.type = "Program";
+  ast.sourceType = ast.program.sourceType;
+  ast.directives = ast.program.directives;
+  ast.body = ast.program.body;
+  delete ast.program;
+
+  if (ast.comments.length) {
+    const lastComment = ast.comments[ast.comments.length - 1];
+
+    if (!ast.tokens.length) {
+      // if no tokens, the program starts at the end of the last comment
+      ast.start = lastComment.end;
+      ast.loc.start.line = lastComment.loc.end.line;
+      ast.loc.start.column = lastComment.loc.end.column;
+    } else {
+      const lastToken = ast.tokens[ast.tokens.length - 1];
+
+      if (lastComment.end > lastToken.end) {
+        // If there is a comment after the last token, the program ends at the
+        // last token and not the comment
+        ast.range[1] = lastToken.end;
+        ast.loc.end.line = lastToken.loc.end.line;
+        ast.loc.end.column = lastToken.loc.end.column;
+      }
+    }
+  } else {
+    if (!ast.tokens.length) {
+      ast.loc.start.line = 1;
+      ast.loc.end.line = 1;
+    }
+  }
+
+  if (ast.body && ast.body.length > 0) {
+    ast.loc.start.line = ast.body[0].loc.start.line;
+    ast.range[0] = ast.body[0].start;
+  }
+}
+
+export default function convertAST(ast, code) {
+  convertNodes(ast, code);
+  convertProgramNode(ast);
+}

eslint/babel-eslint-parser/src/convert/convertComments.js

@@ -1,4 +1,4 @@
-export default function(comments) {
+export default function convertComments(comments) {
   for (let i = 0; i < comments.length; i++) {
     const comment = comments[i];
     if (comment.type === "CommentBlock") {

eslint/babel-eslint-parser/src/convert/convertTokens.js

@@ -1,6 +1,97 @@
 import { tokTypes as tt } from "@babel/core";
 
-export default function(token, source) {
+function convertTemplateType(tokens) {
+  let curlyBrace = null;
+  let templateTokens = [];
+  const result = [];
+
+  function addTemplateType() {
+    const start = templateTokens[0];
+    const end = templateTokens[templateTokens.length - 1];
+
+    const value = templateTokens.reduce((result, token) => {
+      if (token.value) {
+        result += token.value;
+      } else if (token.type !== tt.template) {
+        result += token.type.label;
+      }
+
+      return result;
+    }, "");
+
+    result.push({
+      type: "Template",
+      value: value,
+      start: start.start,
+      end: end.end,
+      loc: {
+        start: start.loc.start,
+        end: end.loc.end,
+      },
+    });
+
+    templateTokens = [];
+  }
+
+  tokens.forEach(token => {
+    switch (token.type) {
+      case tt.backQuote:
+        if (curlyBrace) {
+          result.push(curlyBrace);
+          curlyBrace = null;
+        }
+
+        templateTokens.push(token);
+
+        if (templateTokens.length > 1) {
+          addTemplateType();
+        }
+
+        break;
+
+      case tt.dollarBraceL:
+        templateTokens.push(token);
+        addTemplateType();
+        break;
+
+      case tt.braceR:
+        if (curlyBrace) {
+          result.push(curlyBrace);
+        }
+
+        curlyBrace = token;
+        break;
+
+      case tt.template:
+        if (curlyBrace) {
+          templateTokens.push(curlyBrace);
+          curlyBrace = null;
+        }
+
+        templateTokens.push(token);
+        break;
+
+      case tt.eof:
+        if (curlyBrace) {
+          result.push(curlyBrace);
+        }
+
+        break;
+
+      default:
+        if (curlyBrace) {
+          result.push(curlyBrace);
+          curlyBrace = null;
+        }
+
+        result.push(token);
+    }
+  });
+
+  return result;
+}
+
+function convertToken(token, source) {
   const type = token.type;
   token.range = [token.start, token.end];
 
@@ -86,3 +177,9 @@ export default function(token, source) {
 
   return token;
 }
+
+export default function convertTokens(tokens, code) {
+  return convertTemplateType(tokens)
+    .filter(t => t.type !== "CommentLine" && t.type !== "CommentBlock")
+    .map(t => convertToken(t, code));
+}

eslint/babel-eslint-parser/src/parse-with-scope.js

@@ -2,7 +2,7 @@ import visitorKeys from "./visitor-keys";
 import analyzeScope from "./analyze-scope";
 import parse from "./parse";
 
-export default function(code, options) {
+export default function parseWithScope(code, options) {
   const ast = parse(code, options);
   const scopeManager = analyzeScope(ast, options);
 

eslint/babel-eslint-parser/src/parse.js

@@ -1,5 +1,5 @@
 import { parseSync as babelParse } from "@babel/core";
-import babylonToEspree from "./babylon-to-espree";
+import convert from "./convert";
 import { normalizeBabelParseConfig } from "./configuration";
 
 export default function parse(code, options) {
@@ -17,7 +17,7 @@ export default function parse(code, options) {
     throw err;
   }
 
-  babylonToEspree(ast, code);
+  convert(ast, code);
 
   return ast;
 }