From e72a336e9b62174c77be79ff6252fb6d780dd238 Mon Sep 17 00:00:00 2001
From: Ben Mosher <me@benmosher.com>
Date: Tue, 29 Jan 2019 05:45:05 -0500
Subject: [PATCH] fix #1266 by moving closure creation out of parsing scope
 (#1275)

---
 CHANGELOG.md                |  9 +++++++++
 docs/rules/no-deprecated.md |  4 ----
 src/ExportMap.js            | 28 +++++++++++++++++++++-------
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a0a3f5ac..f21cfeb2c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This change log adheres to standards from [Keep a CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
+### Added
+- `typescript` config ([#1257], thanks [@kirill-konshin])
 
+### Fixed
+- Memory leak of `SourceCode` objects for all parsed dependencies, resolved. (issue [#1266], thanks [@asapach] and [@sergei-startsev] for digging in)
 
 ## [2.15.0] - 2019-01-22
 ### Added
@@ -506,6 +510,7 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#1257]: https://github.com/benmosher/eslint-plugin-import/pull/1257
 [#1232]: https://github.com/benmosher/eslint-plugin-import/pull/1232
 [#1176]: https://github.com/benmosher/eslint-plugin-import/pull/1176
 [#1163]: https://github.com/benmosher/eslint-plugin-import/pull/1163
@@ -595,6 +600,7 @@ for info on changes for earlier releases.
 [#314]: https://github.com/benmosher/eslint-plugin-import/pull/314
 [#912]: https://github.com/benmosher/eslint-plugin-import/pull/912
 
+[#1266]: https://github.com/benmosher/eslint-plugin-import/issues/1266
 [#1175]: https://github.com/benmosher/eslint-plugin-import/issues/1175
 [#1058]: https://github.com/benmosher/eslint-plugin-import/issues/1058
 [#931]: https://github.com/benmosher/eslint-plugin-import/issues/931
@@ -791,3 +797,6 @@ for info on changes for earlier releases.
 [@pzhine]: https://github.com/pzhine
 [@st-sloth]: https://github.com/st-sloth
 [@ljqx]: https://github.com/ljqx
+[@kirill-konshin]: https://github.com/kirill-konshin
+[@asapach]: https://github.com/asapach
+[@sergei-startsev]: https://github.com/sergei-startsev
diff --git a/docs/rules/no-deprecated.md b/docs/rules/no-deprecated.md
index 7583651f3..fae7d8daf 100644
--- a/docs/rules/no-deprecated.md
+++ b/docs/rules/no-deprecated.md
@@ -1,9 +1,5 @@
 # import/no-deprecated
 
-**Stage: 0**
-
-**NOTE**: this rule is currently a work in progress. There may be "breaking" changes: most likely, additional cases that are flagged.
-
 Reports use of a deprecated name, as indicated by a JSDoc block with a `@deprecated`
 tag or TomDoc `Deprecated: ` comment.
 
diff --git a/src/ExportMap.js b/src/ExportMap.js
index c8335d9c8..38aedc6d6 100644
--- a/src/ExportMap.js
+++ b/src/ExportMap.js
@@ -192,8 +192,6 @@ export default class ExportMap {
 
 /**
  * parse docs from the first node that has leading comments
- * @param  {...[type]} nodes [description]
- * @return {{doc: object}}
  */
 function captureDoc(source, docStyleParsers) {
   const metadata = {}
@@ -202,9 +200,17 @@ function captureDoc(source, docStyleParsers) {
   // 'some' short-circuits on first 'true'
   nodes.some(n => {
     try {
+
+      let leadingComments
+
       // n.leadingComments is legacy `attachComments` behavior
-      let leadingComments = n.leadingComments || source.getCommentsBefore(n)
-      if (leadingComments.length === 0) return false
+      if ('leadingComments' in n) {
+        leadingComments = n.leadingComments
+      } else if (n.range) {
+        leadingComments = source.getCommentsBefore(n)
+      }
+
+      if (!leadingComments || leadingComments.length === 0) return false
 
       for (let name in docStyleParsers) {
         const doc = docStyleParsers[name](leadingComments)
@@ -346,8 +352,6 @@ ExportMap.parse = function (path, content, context) {
     docStyleParsers[style] = availableDocStyleParsers[style]
   })
 
-  const source = makeSourceCode(content, ast)
-
   // attempt to collect module doc
   if (ast.comments) {
     ast.comments.some(c => {
@@ -400,7 +404,7 @@ ExportMap.parse = function (path, content, context) {
     const existing = m.imports.get(p)
     if (existing != null) return existing.getter
 
-    const getter = () => ExportMap.for(childContext(p, context))
+    const getter = thunkFor(p, context)
     m.imports.set(p, {
       getter,
       source: {  // capturing actual node reference holds full AST in memory!
@@ -411,6 +415,7 @@ ExportMap.parse = function (path, content, context) {
     return getter
   }
 
+  const source = makeSourceCode(content, ast)
 
   ast.body.forEach(function (n) {
 
@@ -496,6 +501,15 @@ ExportMap.parse = function (path, content, context) {
   return m
 }
 
+/**
+ * The creation of this closure is isolated from other scopes
+ * to avoid over-retention of unrelated variables, which has
+ * caused memory leaks. See #1266.
+ */
+function thunkFor(p, context) {
+  return () => ExportMap.for(childContext(p, context))
+}
+
 
 /**
  * Traverse a pattern/identifier node, calling 'callback'