Offer semantic services alongside AST

lib/ast-converter.js

@@ -73,5 +73,8 @@ module.exports = (ast, extra) => {
     estree.comments = convertComments(ast, extra.code);
   }
 
-  return estree;
+  const astMaps = convert.getASTMaps();
+  convert.resetASTMaps();
+
+  return { estree, astMaps };
 };

lib/convert.js

@@ -25,6 +25,18 @@ const SyntaxKind = nodeUtils.SyntaxKind;
 // Public
 //------------------------------------------------------------------------------
 
+let esTreeNodeToTSNodeMap = new WeakMap();
+let tsNodeToESTreeNodeMap = new WeakMap();
+
+function resetASTMaps() {
+  esTreeNodeToTSNodeMap = new WeakMap();
+  tsNodeToESTreeNodeMap = new WeakMap();
+}
+
+function getASTMaps() {
+  return { esTreeNodeToTSNodeMap, tsNodeToESTreeNodeMap };
+}
+
 /**
  * Converts a TypeScript node into an ESTree node
  * @param  {Object} config configuration options for the conversion
@@ -53,7 +65,7 @@ module.exports = function convert(config) {
    */
   let result = {
     type: '',
-    range: [node.getStart(), node.end],
+    range: [node.getStart(ast), node.end],
     loc: nodeUtils.getLoc(node, ast)
   };
 
@@ -132,7 +144,7 @@ module.exports = function convert(config) {
         if (nodeUtils.isTypeKeyword(typeArgument.kind)) {
           return {
             type: AST_NODE_TYPES[`TS${SyntaxKind[typeArgument.kind]}`],
-            range: [typeArgument.getStart(), typeArgument.getEnd()],
+            range: [typeArgument.getStart(ast), typeArgument.getEnd()],
             loc: nodeUtils.getLoc(typeArgument, ast)
           };
         }
@@ -146,7 +158,7 @@ module.exports = function convert(config) {
         }
         return {
           type: AST_NODE_TYPES.TSTypeReference,
-          range: [typeArgument.getStart(), typeArgument.getEnd()],
+          range: [typeArgument.getStart(ast), typeArgument.getEnd()],
           loc: nodeUtils.getLoc(typeArgument, ast),
           typeName: convertChild(typeArgument.typeName || typeArgument),
           typeParameters: typeArgument.typeArguments
@@ -199,7 +211,7 @@ module.exports = function convert(config) {
 
         return {
           type: AST_NODE_TYPES.TSTypeParameter,
-          range: [typeParameter.getStart(), typeParameter.getEnd()],
+          range: [typeParameter.getStart(ast), typeParameter.getEnd()],
           loc: nodeUtils.getLoc(typeParameter, ast),
           name,
           constraint,
@@ -266,7 +278,7 @@ module.exports = function convert(config) {
       const expression = convertChild(decorator.expression);
       return {
         type: AST_NODE_TYPES.Decorator,
-        range: [decorator.getStart(), decorator.end],
+        range: [decorator.getStart(ast), decorator.end],
         loc: nodeUtils.getLoc(decorator, ast),
         expression
       };
@@ -477,7 +489,11 @@ module.exports = function convert(config) {
       });
 
       result.range[1] = node.endOfFileToken.end;
-      result.loc = nodeUtils.getLocFor(node.getStart(), result.range[1], ast);
+      result.loc = nodeUtils.getLocFor(
+        node.getStart(ast),
+        result.range[1],
+        ast
+      );
       break;
 
     case SyntaxKind.Block:
@@ -934,11 +950,12 @@ module.exports = function convert(config) {
             return false;
           }
           return nodeUtils.getTextForTokenKind(token.kind) === '(';
-        }
+        },
+        ast
       );
 
       const methodLoc = ast.getLineAndCharacterOfPosition(
-          openingParen.getStart()
+          openingParen.getStart(ast)
         ),
         nodeIsMethod = node.kind === SyntaxKind.MethodDeclaration,
         method = {
@@ -1069,10 +1086,10 @@ module.exports = function convert(config) {
         };
 
       const constructorIdentifierLocStart = ast.getLineAndCharacterOfPosition(
-          firstConstructorToken.getStart()
+          firstConstructorToken.getStart(ast)
         ),
         constructorIdentifierLocEnd = ast.getLineAndCharacterOfPosition(
-          firstConstructorToken.getEnd()
+          firstConstructorToken.getEnd(ast)
         ),
         constructorIsComputed =
           !!node.name && nodeUtils.isComputedProperty(node.name);
@@ -1084,7 +1101,10 @@ module.exports = function convert(config) {
           type: AST_NODE_TYPES.Literal,
           value: 'constructor',
           raw: node.name.getText(),
-          range: [firstConstructorToken.getStart(), firstConstructorToken.end],
+          range: [
+            firstConstructorToken.getStart(ast),
+            firstConstructorToken.end
+          ],
           loc: {
             start: {
               line: constructorIdentifierLocStart.line + 1,
@@ -1100,7 +1120,10 @@ module.exports = function convert(config) {
         constructorKey = {
           type: AST_NODE_TYPES.Identifier,
           name: 'constructor',
-          range: [firstConstructorToken.getStart(), firstConstructorToken.end],
+          range: [
+            firstConstructorToken.getStart(ast),
+            firstConstructorToken.end
+          ],
           loc: {
             start: {
               line: constructorIdentifierLocStart.line + 1,
@@ -1233,9 +1256,9 @@ module.exports = function convert(config) {
             type: AST_NODE_TYPES.AssignmentPattern,
             left: convertChild(node.name),
             right: convertChild(node.initializer),
-            range: [node.name.getStart(), node.initializer.end],
+            range: [node.name.getStart(ast), node.initializer.end],
             loc: nodeUtils.getLocFor(
-              node.name.getStart(),
+              node.name.getStart(ast),
               node.initializer.end,
               ast
             )
@@ -1292,7 +1315,7 @@ module.exports = function convert(config) {
           {
             type: AST_NODE_TYPES.TemplateElement,
             value: {
-              raw: ast.text.slice(node.getStart() + 1, node.end - 1),
+              raw: ast.text.slice(node.getStart(ast) + 1, node.end - 1),
               cooked: node.text
             },
             tail: true,
@@ -1335,7 +1358,10 @@ module.exports = function convert(config) {
       Object.assign(result, {
         type: AST_NODE_TYPES.TemplateElement,
         value: {
-          raw: ast.text.slice(node.getStart() + 1, node.end - (tail ? 1 : 2)),
+          raw: ast.text.slice(
+            node.getStart(ast) + 1,
+            node.end - (tail ? 1 : 2)
+          ),
           cooked: node.text
         },
         tail
@@ -1426,7 +1452,7 @@ module.exports = function convert(config) {
       if (node.modifiers) {
         return {
           type: AST_NODE_TYPES.TSParameterProperty,
-          range: [node.getStart(), node.end],
+          range: [node.getStart(ast), node.end],
           loc: nodeUtils.getLoc(node, ast),
           accessibility: nodeUtils.getTSNodeAccessibility(node) || undefined,
           readonly:
@@ -1523,8 +1549,8 @@ module.exports = function convert(config) {
           body: [],
 
           // TODO: Fix location info
-          range: [openBrace.getStart(), result.range[1]],
-          loc: nodeUtils.getLocFor(openBrace.getStart(), node.end, ast)
+          range: [openBrace.getStart(ast), result.range[1]],
+          loc: nodeUtils.getLocFor(openBrace.getStart(ast), node.end, ast)
         },
         superClass:
           superClass && superClass.types[0]
@@ -2142,7 +2168,7 @@ module.exports = function convert(config) {
         type: AST_NODE_TYPES.VariableDeclarator,
         id: convertChild(node.name),
         init: convertChild(node.type),
-        range: [node.name.getStart(), node.end]
+        range: [node.name.getStart(ast), node.end]
       };
 
       typeAliasDeclarator.loc = nodeUtils.getLocFor(
@@ -2299,8 +2325,12 @@ module.exports = function convert(config) {
       const interfaceBody = {
         type: AST_NODE_TYPES.TSInterfaceBody,
         body: node.members.map(member => convertChild(member)),
-        range: [interfaceOpenBrace.getStart(), result.range[1]],
-        loc: nodeUtils.getLocFor(interfaceOpenBrace.getStart(), node.end, ast)
+        range: [interfaceOpenBrace.getStart(ast), result.range[1]],
+        loc: nodeUtils.getLocFor(
+          interfaceOpenBrace.getStart(ast),
+          node.end,
+          ast
+        )
       };
 
       Object.assign(result, {
@@ -2411,5 +2441,11 @@ module.exports = function convert(config) {
       deeplyCopy();
   }
 
+  tsNodeToESTreeNodeMap.set(node, result);
+  esTreeNodeToTSNodeMap.set(result, node);
+
   return result;
 };
+
+module.exports.getASTMaps = getASTMaps;
+module.exports.resetASTMaps = resetASTMaps;

lib/node-utils.js

@@ -295,7 +295,7 @@ function getLocFor(start, end, ast) {
  * @returns {Object}             the loc data
  */
 function getLoc(nodeOrToken, ast) {
-  return getLocFor(nodeOrToken.getStart(), nodeOrToken.end, ast);
+  return getLocFor(nodeOrToken.getStart(ast), nodeOrToken.end, ast);
 }
 
 /**
@@ -407,28 +407,44 @@ function hasStaticModifierFlag(node) {
  * Finds the next token based on the previous one and its parent
  * @param {TSToken} previousToken The previous TSToken
  * @param {TSNode} parent The parent TSNode
+ * @param {ts.SourceFileLike} ast The TS AST
  * @returns {TSToken} the next TSToken
  */
-function findNextToken(previousToken, parent) {
-  /**
-   * TODO: Remove dependency on private TypeScript method
-   */
-  return ts.findNextToken(previousToken, parent);
+function findNextToken(previousToken, parent, ast) {
+  return find(parent);
+
+  function find(n) {
+    if (ts.isToken(n) && n.pos === previousToken.end) {
+      // this is token that starts at the end of previous token - return it
+      return n;
+    }
+    return firstDefined(n.getChildren(ast), child => {
+      const shouldDiveInChildNode =
+        // previous token is enclosed somewhere in the child
+        (child.pos <= previousToken.pos && child.end > previousToken.end) ||
+        // previous token ends exactly at the beginning of child
+        child.pos === previousToken.end;
+      return shouldDiveInChildNode && nodeHasTokens(child, ast)
+        ? find(child)
+        : undefined;
+    });
+  }
 }
 
 /**
  * Find the first matching token based on the given predicate function.
  * @param {TSToken} previousToken The previous TSToken
  * @param {TSNode} parent The parent TSNode
  * @param {Function} predicate The predicate function to apply to each checked token
+ * @param {ts.SourceFileLike} ast The TS AST
  * @returns {TSToken|undefined} a matching TSToken
  */
-function findFirstMatchingToken(previousToken, parent, predicate) {
+function findFirstMatchingToken(previousToken, parent, predicate, ast) {
   while (previousToken) {
     if (predicate(previousToken)) {
       return previousToken;
     }
-    previousToken = findNextToken(previousToken, parent);
+    previousToken = findNextToken(previousToken, parent, ast);
   }
   return undefined;
 }
@@ -536,9 +552,9 @@ function fixExports(node, result, ast) {
       lastModifier = node.modifiers[node.modifiers.length - 1],
       declarationIsDefault =
         nextModifier && nextModifier.kind === SyntaxKind.DefaultKeyword,
-      varToken = findNextToken(lastModifier, ast);
+      varToken = findNextToken(lastModifier, ast, ast);
 
-    result.range[0] = varToken.getStart();
+    result.range[0] = varToken.getStart(ast);
     result.loc = getLocFor(result.range[0], result.range[1], ast);
 
     const declarationType = declarationIsDefault
@@ -548,8 +564,8 @@ function fixExports(node, result, ast) {
     const newResult = {
       type: declarationType,
       declaration: result,
-      range: [exportKeyword.getStart(), result.range[1]],
-      loc: getLocFor(exportKeyword.getStart(), result.range[1], ast)
+      range: [exportKeyword.getStart(ast), result.range[1]],
+      loc: getLocFor(exportKeyword.getStart(ast), result.range[1], ast)
     };
 
     if (!declarationIsDefault) {
@@ -680,7 +696,7 @@ function convertToken(token, ast) {
   const start =
       token.kind === SyntaxKind.JsxText
         ? token.getFullStart()
-        : token.getStart(),
+        : token.getStart(ast),
     end = token.getEnd(),
     value = ast.text.slice(start, end),
     newToken = {
@@ -725,7 +741,7 @@ function convertTokens(ast) {
         result.push(converted);
       }
     } else {
-      node.getChildren().forEach(walk);
+      node.getChildren(ast).forEach(walk);
     }
   }
   walk(ast);
@@ -779,3 +795,37 @@ function createError(ast, start, message) {
     message
   };
 }
+
+/**
+ * @param {ts.Node} n the TSNode
+ * @param {ts.SourceFileLike} ast the TS AST
+ */
+function nodeHasTokens(n, ast) {
+  // If we have a token or node that has a non-zero width, it must have tokens.
+  // Note: getWidth() does not take trivia into account.
+  return n.kind === SyntaxKind.EndOfFileToken
+    ? !!n.jsDoc
+    : n.getWidth(ast) !== 0;
+}
+
+/**
+ * Like `forEach`, but suitable for use with numbers and strings (which may be falsy).
+ * @template T
+ * @template U
+ * @param {ReadonlyArray<T>|undefined} array
+ * @param {(element: T, index: number) => (U|undefined)} callback
+ * @returns {U|undefined}
+ */
+function firstDefined(array, callback) {
+  if (array === undefined) {
+    return undefined;
+  }
+
+  for (let i = 0; i < array.length; i++) {
+    const result = callback(array[i], i);
+    if (result !== undefined) {
+      return result;
+    }
+  }
+  return undefined;
+}