From e0d1fc3c92739c42363fc91a0d833e07ad352e17 Mon Sep 17 00:00:00 2001
From: Alexandre BODIN <bodin.alex@gmail.com>
Date: Tue, 13 Jun 2017 23:48:30 +0200
Subject: [PATCH 1/3] Add support for beginning pipe un union types

---
 .../__tests__/schema-kitchen-sink.graphql     |  2 ++
 src/language/__tests__/schema-parser-test.js  | 22 +++++++++++++++++++
 src/language/__tests__/schema-printer-test.js |  2 ++
 src/language/parser.js                        |  3 +++
 4 files changed, 29 insertions(+)

diff --git a/src/language/__tests__/schema-kitchen-sink.graphql b/src/language/__tests__/schema-kitchen-sink.graphql
index a56c0e4cc6..0686414894 100644
--- a/src/language/__tests__/schema-kitchen-sink.graphql
+++ b/src/language/__tests__/schema-kitchen-sink.graphql
@@ -37,6 +37,8 @@ union Feed = Story | Article | Advert
 
 union AnnotatedUnion @onUnion = A | B
 
+union AnnotatedUnionTwo @onUnion = | A | B
+
 scalar CustomScalar
 
 scalar AnnotatedScalar @onScalar
diff --git a/src/language/__tests__/schema-parser-test.js b/src/language/__tests__/schema-parser-test.js
index 3a15e300e5..7b3ffd1344 100644
--- a/src/language/__tests__/schema-parser-test.js
+++ b/src/language/__tests__/schema-parser-test.js
@@ -457,6 +457,28 @@ type Hello {
     expect(printJson(doc)).to.equal(printJson(expected));
   });
 
+  it('Union with two types and begining pipe', () => {
+    const body = 'union Hello = | Wo | Rld';
+    const doc = parse(body);
+    const expected = {
+      kind: 'Document',
+      definitions: [
+        {
+          kind: 'UnionTypeDefinition',
+          name: nameNode('Hello', { start: 6, end: 11 }),
+          directives: [],
+          types: [
+            typeNode('Wo', { start: 16, end: 18 }),
+            typeNode('Rld', { start: 21, end: 24 }),
+          ],
+          loc: { start: 0, end: 24 },
+        }
+      ],
+      loc: { start: 0, end: 24 },
+    };
+    expect(printJson(doc)).to.equal(printJson(expected));
+  });
+
   it('Union with two types', () => {
     const body = 'union Hello = Wo | Rld';
     const doc = parse(body);
diff --git a/src/language/__tests__/schema-printer-test.js b/src/language/__tests__/schema-printer-test.js
index 4fa56275bb..89558f8a9f 100644
--- a/src/language/__tests__/schema-printer-test.js
+++ b/src/language/__tests__/schema-printer-test.js
@@ -83,6 +83,8 @@ union Feed = Story | Article | Advert
 
 union AnnotatedUnion @onUnion = A | B
 
+union AnnotatedUnionTwo @onUnion = A | B
+
 scalar CustomScalar
 
 scalar AnnotatedScalar @onScalar
diff --git a/src/language/parser.js b/src/language/parser.js
index ea4ac0f68c..03bb35097e 100644
--- a/src/language/parser.js
+++ b/src/language/parser.js
@@ -943,6 +943,9 @@ function parseUnionTypeDefinition(lexer: Lexer<*>): UnionTypeDefinitionNode {
  */
 function parseUnionMembers(lexer: Lexer<*>): Array<NamedTypeNode> {
   const members = [];
+  if (peek(lexer, TokenKind.PIPE)) {
+    skip(lexer, TokenKind.PIPE);
+  }
   do {
     members.push(parseNamedType(lexer));
   } while (skip(lexer, TokenKind.PIPE));

From 4cb3ff008906c0a08833c0dc7e54cfbb65a4b459 Mon Sep 17 00:00:00 2001
From: Alexandre BODIN <bodin.alex@gmail.com>
Date: Wed, 14 Jun 2017 00:30:32 +0200
Subject: [PATCH 2/3] Add use cases with ending vertical bar or empty list of
 types throwing

---
 src/language/__tests__/schema-parser-test.js | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/language/__tests__/schema-parser-test.js b/src/language/__tests__/schema-parser-test.js
index 7b3ffd1344..9b97b5dd1e 100644
--- a/src/language/__tests__/schema-parser-test.js
+++ b/src/language/__tests__/schema-parser-test.js
@@ -457,7 +457,7 @@ type Hello {
     expect(printJson(doc)).to.equal(printJson(expected));
   });
 
-  it('Union with two types and begining pipe', () => {
+  it('Union with two types and leading vertical bar', () => {
     const body = 'union Hello = | Wo | Rld';
     const doc = parse(body);
     const expected = {
@@ -479,6 +479,21 @@ type Hello {
     expect(printJson(doc)).to.equal(printJson(expected));
   });
 
+  it('Union with no types and leading vertical bar', () => {
+    const body = 'union Hello = |';
+    expect(() => parse(body)).to.throw();
+  });
+
+  it('Union with types and ending vertical bar', () => {
+    const body = 'union Hello = Wo | Rld |';
+    expect(() => parse(body)).to.throw();
+  });
+
+  it('Union with types , leanding and ending vertical bar', () => {
+    const body = 'union Hello = | Wo | Rld |';
+    expect(() => parse(body)).to.throw();
+  });
+
   it('Union with two types', () => {
     const body = 'union Hello = Wo | Rld';
     const doc = parse(body);

From 7fc9fc0ba1d8f253a6c5876d71e61ad29aed91d6 Mon Sep 17 00:00:00 2001
From: Alexandre BODIN <bodin.alex@gmail.com>
Date: Wed, 14 Jun 2017 00:37:41 +0200
Subject: [PATCH 3/3] Add doucle bar testing

---
 src/language/__tests__/schema-parser-test.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/language/__tests__/schema-parser-test.js b/src/language/__tests__/schema-parser-test.js
index 9b97b5dd1e..0e76282679 100644
--- a/src/language/__tests__/schema-parser-test.js
+++ b/src/language/__tests__/schema-parser-test.js
@@ -489,6 +489,21 @@ type Hello {
     expect(() => parse(body)).to.throw();
   });
 
+  it('Union with types and double vertical bar at the beginning', () => {
+    const body = 'union Hello = || Wo | Rld';
+    expect(() => parse(body)).to.throw();
+  });
+
+  it('Union with types and double vertical bar in the middle', () => {
+    const body = 'union Hello = Wo || Rld';
+    expect(() => parse(body)).to.throw();
+  });
+
+  it('Union with types and double vertical bar at the end', () => {
+    const body = 'union Hello = | Wo | Rld ||';
+    expect(() => parse(body)).to.throw();
+  });
+
   it('Union with types , leanding and ending vertical bar', () => {
     const body = 'union Hello = | Wo | Rld |';
     expect(() => parse(body)).to.throw();