From a269bc8765797d9618a754267aec74984095d43d Mon Sep 17 00:00:00 2001
From: Daniel Jasper <djasper@google.com>
Date: Tue, 22 Mar 2016 14:32:20 +0000
Subject: [PATCH] clang-format: [JS] do not wrap ES6 imports/exports.

"import ... from '...';" and "export ... from '...';" should be treated
the same as goog.require/provide/module/forwardDeclare calls.

Patch by Martin Probst.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@264055 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Format/FormatToken.h          |  2 ++
 lib/Format/TokenAnnotator.cpp     | 26 ++++++++++++++++++++-----
 unittests/Format/FormatTestJS.cpp | 32 +++++++++++++++----------------
 3 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/lib/Format/FormatToken.h b/lib/Format/FormatToken.h
index 64d236bfb3..f15c9e998e 100644
--- a/lib/Format/FormatToken.h
+++ b/lib/Format/FormatToken.h
@@ -537,6 +537,7 @@ struct AdditionalKeywords {
 
     kw_finally = &IdentTable.get("finally");
     kw_function = &IdentTable.get("function");
+    kw_from = &IdentTable.get("from");
     kw_import = &IdentTable.get("import");
     kw_is = &IdentTable.get("is");
     kw_let = &IdentTable.get("let");
@@ -583,6 +584,7 @@ struct AdditionalKeywords {
   // JavaScript keywords.
   IdentifierInfo *kw_finally;
   IdentifierInfo *kw_function;
+  IdentifierInfo *kw_from;
   IdentifierInfo *kw_import;
   IdentifierInfo *kw_is;
   IdentifierInfo *kw_let;
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 69b703d03c..b57faaad8b 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -764,13 +764,30 @@ public:
         return LT_ImportStatement;
     }
 
+    // import {...} from '...';
+    if (Style.Language == FormatStyle::LK_JavaScript &&
+        CurrentToken->is(Keywords.kw_import))
+      return LT_ImportStatement;
+
     bool KeywordVirtualFound = false;
     bool ImportStatement = false;
     while (CurrentToken) {
       if (CurrentToken->is(tok::kw_virtual))
         KeywordVirtualFound = true;
-      if (isImportStatement(*CurrentToken))
-        ImportStatement = true;
+      if (Style.Language == FormatStyle::LK_JavaScript) {
+        // export {...} from '...';
+        // An export followed by "from 'some string';" is a re-export from
+        // another module identified by a URI and is treated as a
+        // LT_ImportStatement (i.e. prevent wraps on it for long URIs).
+        // Just "export {...};" or "export class ..." should not be treated as
+        // an import in this sense.
+        if (Line.First->is(tok::kw_export) &&
+            CurrentToken->is(Keywords.kw_from) && CurrentToken->Next &&
+            CurrentToken->Next->isStringLiteral())
+          ImportStatement = true;
+        if (isClosureImportStatement(*CurrentToken))
+          ImportStatement = true;
+      }
       if (!consumeToken())
         return LT_Invalid;
     }
@@ -790,11 +807,10 @@ public:
   }
 
 private:
-  bool isImportStatement(const FormatToken &Tok) {
+  bool isClosureImportStatement(const FormatToken &Tok) {
     // FIXME: Closure-library specific stuff should not be hard-coded but be
     // configurable.
-    return Style.Language == FormatStyle::LK_JavaScript &&
-           Tok.TokenText == "goog" && Tok.Next && Tok.Next->is(tok::period) &&
+    return Tok.TokenText == "goog" && Tok.Next && Tok.Next->is(tok::period) &&
            Tok.Next->Next && (Tok.Next->Next->TokenText == "module" ||
                               Tok.Next->Next->TokenText == "provide" ||
                               Tok.Next->Next->TokenText == "require" ||
diff --git a/unittests/Format/FormatTestJS.cpp b/unittests/Format/FormatTestJS.cpp
index c39667613c..73f3afbaf0 100644
--- a/unittests/Format/FormatTestJS.cpp
+++ b/unittests/Format/FormatTestJS.cpp
@@ -942,21 +942,10 @@ TEST_F(FormatTestJS, Modules) {
   verifyFormat("import SomeThing from 'some/module.js';");
   verifyFormat("import {X, Y} from 'some/module.js';");
   verifyFormat("import a, {X, Y} from 'some/module.js';");
-  verifyFormat("import {\n"
-               "  VeryLongImportsAreAnnoying,\n"
-               "  VeryLongImportsAreAnnoying,\n"
-               "  VeryLongImportsAreAnnoying,\n"
-               "  VeryLongImportsAreAnnoying\n"
+  verifyFormat("import {VeryLongImportsAreAnnoying, VeryLongImportsAreAnnoying,"
+               " VeryLongImportsAreAnnoying, VeryLongImportsAreAnnoying"
                "} from 'some/module.js';");
-  verifyFormat("import {\n"
-               "  X,\n"
-               "  Y,\n"
-               "} from 'some/module.js';");
-  verifyFormat("import {\n"
-               "  X,\n"
-               "  Y,\n"
-               "} from\n    'some/long/module.js';",
-               getGoogleJSStyleWithColumns(20));
+  verifyFormat("import {X, Y,} from 'some/module.js';");
   verifyFormat("import {X as myLocalX, Y as myLocalY} from 'some/module.js';");
   verifyFormat("import * as lib from 'some/module.js';");
   verifyFormat("var x = {import: 1};\nx.import = 2;");
@@ -970,10 +959,19 @@ TEST_F(FormatTestJS, Modules) {
   verifyFormat("export const x = 12;");
   verifyFormat("export default class X {}");
   verifyFormat("export {X, Y} from 'some/module.js';");
+  verifyFormat("export {X, Y,} from 'some/module.js';");
+  verifyFormat("export {SomeVeryLongExport as X, "
+               "SomeOtherVeryLongExport as Y} from 'some/module.js';");
+  // export without 'from' is wrapped.
+  verifyFormat("export let someRatherLongVariableName =\n"
+               "    someSurprisinglyLongVariable + someOtherRatherLongVar;");
+  // ... but not if from is just an identifier.
   verifyFormat("export {\n"
-               "  X,\n"
-               "  Y,\n"
-               "} from 'some/module.js';");
+               "  from as from,\n"
+               "  someSurprisinglyLongVariable\n"
+               "      as from\n"
+               "};",
+               getGoogleJSStyleWithColumns(20));
   verifyFormat("export class C {\n"
                "  x: number;\n"
                "  y: string;\n"
-- 
2.40.0