From c14c9bd665525865f023b7214bbaf3d0124563dd Mon Sep 17 00:00:00 2001
From: Ben Munro <benmunro@amazon.com>
Date: Mon, 7 Oct 2019 18:03:41 +0200
Subject: [PATCH] [Fix] `named`/`ExportMap`: Fix ExportMap for a merged
 typescript namespace

A typescript namespace may be declared multiple times, it is then merged
together and considered to be a single declaration from consuming code.
In the case where a merged namespace is assigned as the export from a
module then the declarations from all the instances of the namespace in
the AST need to be considered as exported.
---
 CHANGELOG.md                                  |  3 ++
 src/ExportMap.js                              | 44 ++++++++++---------
 .../typescript-export-assign-merged.d.ts      | 41 +++++++++++++++++
 tests/src/rules/named.js                      |  2 +-
 4 files changed, 68 insertions(+), 22 deletions(-)
 create mode 100644 tests/files/typescript-export-assign-merged.d.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6e1fcd225..7a9c6519f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 
 ### Fixed
 - `default`: make error message less confusing ([#1470], thanks [@golopot])
+- Support export of a merged typescript namespace declaration ([#1495], thanks [@benmunro])
 
 ## [2.18.2] - 2019-07-19
 - Skip warning on type interfaces ([#1425], thanks [@lencioni])
@@ -609,6 +610,7 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#1495]: https://github.com/benmosher/eslint-plugin-import/pull/1495
 [#1472]: https://github.com/benmosher/eslint-plugin-import/pull/1472
 [#1470]: https://github.com/benmosher/eslint-plugin-import/pull/1470
 [#1436]: https://github.com/benmosher/eslint-plugin-import/pull/1436
@@ -992,3 +994,4 @@ for info on changes for earlier releases.
 [@atikenny]: https://github.com/atikenny
 [@schmidsi]: https://github.com/schmidsi
 [@TrevorBurnham]: https://github.com/TrevorBurnham
+[@benmunro]: https://github.com/benmunro
diff --git a/src/ExportMap.js b/src/ExportMap.js
index ebeb4fad7..c9544c9c8 100644
--- a/src/ExportMap.js
+++ b/src/ExportMap.js
@@ -514,30 +514,32 @@ ExportMap.parse = function (path, content, context) {
 
     // This doesn't declare anything, but changes what's being exported.
     if (n.type === 'TSExportAssignment') {
-      const moduleDecl = ast.body.find((bodyNode) =>
+      const moduleDecls = ast.body.filter((bodyNode) =>
         bodyNode.type === 'TSModuleDeclaration' && bodyNode.id.name === n.expression.name
       )
-      if (moduleDecl && moduleDecl.body && moduleDecl.body.body) {
-        moduleDecl.body.body.forEach((moduleBlockNode) => {
-          // Export-assignment exports all members in the namespace, explicitly exported or not.
-          const exportedDecl = moduleBlockNode.type === 'ExportNamedDeclaration' ?
-            moduleBlockNode.declaration :
-            moduleBlockNode
-
-          if (exportedDecl.type === 'VariableDeclaration') {
-            exportedDecl.declarations.forEach((decl) =>
-              recursivePatternCapture(decl.id,(id) => m.namespace.set(
-                id.name,
-                captureDoc(source, docStyleParsers, decl, exportedDecl, moduleBlockNode))
+      moduleDecls.forEach((moduleDecl) => {
+        if (moduleDecl && moduleDecl.body && moduleDecl.body.body) {
+          moduleDecl.body.body.forEach((moduleBlockNode) => {
+            // Export-assignment exports all members in the namespace, explicitly exported or not.
+            const exportedDecl = moduleBlockNode.type === 'ExportNamedDeclaration' ?
+              moduleBlockNode.declaration :
+              moduleBlockNode
+
+            if (exportedDecl.type === 'VariableDeclaration') {
+              exportedDecl.declarations.forEach((decl) =>
+                recursivePatternCapture(decl.id,(id) => m.namespace.set(
+                  id.name,
+                  captureDoc(source, docStyleParsers, decl, exportedDecl, moduleBlockNode))
+                )
               )
-            )
-          } else {
-            m.namespace.set(
-              exportedDecl.id.name,
-              captureDoc(source, docStyleParsers, moduleBlockNode))
-          }
-        })
-      }
+            } else {
+              m.namespace.set(
+                exportedDecl.id.name,
+                captureDoc(source, docStyleParsers, moduleBlockNode))
+            }
+          })
+        }
+      })
     }
   })
 
diff --git a/tests/files/typescript-export-assign-merged.d.ts b/tests/files/typescript-export-assign-merged.d.ts
new file mode 100644
index 000000000..377a10d20
--- /dev/null
+++ b/tests/files/typescript-export-assign-merged.d.ts
@@ -0,0 +1,41 @@
+export = AssignedNamespace;
+
+declare namespace AssignedNamespace {
+  type MyType = string
+  enum MyEnum {
+    Foo,
+    Bar,
+    Baz
+  }
+}
+
+declare namespace AssignedNamespace {
+  interface Foo {
+    native: string | number
+    typedef: MyType
+    enum: MyEnum
+  }
+
+  abstract class Bar {
+    abstract foo(): Foo
+
+    method();
+  }
+
+  export function getFoo() : MyType;
+
+  export module MyModule {
+    export function ModuleFunction();
+  }
+
+  export namespace MyNamespace {
+    export function NamespaceFunction();
+
+    export module NSModule {
+      export function NSModuleFunction();
+    }
+  }
+
+  // Export-assignment exports all members in the namespace, explicitly exported or not.
+  // interface NotExported {}
+}
diff --git a/tests/src/rules/named.js b/tests/src/rules/named.js
index 9e15a34b0..90e07ba39 100644
--- a/tests/src/rules/named.js
+++ b/tests/src/rules/named.js
@@ -284,7 +284,7 @@ ruleTester.run('named (export *)', rule, {
 
 context('Typescript', function () {
   getTSParsers().forEach((parser) => {
-    ['typescript', 'typescript-declare', 'typescript-export-assign'].forEach((source) => {
+    ['typescript', 'typescript-declare', 'typescript-export-assign', 'typescript-export-assign-merged'].forEach((source) => {
       ruleTester.run(`named`, rule, {
         valid: [
           test({