Fix AstPrinter to print field descriptions (#2808)

* Fix AstPrinter to print field descriptions

* consider compact mode

* fix autoformatted lines

* fix autoformatted imports

* fix `IntrospectionResultToSchemaTest.groovy` test

* fix `IntrospectionResultToSchemaTest.groovy` test

src/main/java/graphql/language/AstPrinter.java

@@ -163,7 +163,7 @@ private NodePrinter<FieldDefinition> fieldDefinition() {
         final String argSep = compactMode ? "," : ", ";
         return (out, node) -> {
             String args;
-            if (hasDescription(node.getInputValueDefinitions()) && !compactMode) {
+            if (hasDescription(Collections.singletonList(node)) && !compactMode) {
                 out.append(description(node));
                 args = join(node.getInputValueDefinitions(), "\n");
                 out.append(node.getName())

src/test/groovy/graphql/introspection/IntrospectionResultToSchemaTest.groovy

@@ -104,13 +104,11 @@ class IntrospectionResultToSchemaTest extends Specification {
 
         then:
         result == """type QueryType implements Query {
-  hero(
-  \"\"\"
+  hero(\"\"\"
   comment about episode
   on two lines
   \"\"\"
-  episode: Episode
-  foo: String = \"bar\"): Character @deprecated(reason: "killed off character")
+  episode: Episode, foo: String = \"bar\"): Character @deprecated(reason: "killed off character")
 }"""
 
     }
@@ -212,9 +210,13 @@ class IntrospectionResultToSchemaTest extends Specification {
         then:
         result == """"A character in the Star Wars Trilogy"
 interface Character {
+  "The id of the character."
   id: String!
+  "The name of the character."
   name: String
+  "The friends of the character, or an empty list if they have none."
   friends: [Character]
+  "Which movies they appear in."
   appearsIn: [Episode]
 }"""
 
@@ -407,22 +409,23 @@ input CharacterInput {
 }
 
 type QueryType {
-  hero(
-  "If omitted, returns the hero of the whole saga. If provided, returns the hero of that particular episode."
+  hero("If omitted, returns the hero of the whole saga. If provided, returns the hero of that particular episode."
   episode: Episode): Character
-  human(
-  "id of the human"
+  human("id of the human"
   id: String!): Human
-  droid(
-  "id of the droid"
+  droid("id of the droid"
   id: String!): Droid
 }
 
 "A character in the Star Wars Trilogy"
 interface Character {
+  "The id of the character."
   id: String!
+  "The name of the character."
   name: String
+  "The friends of the character, or an empty list if they have none."
   friends: [Character]
+  "Which movies they appear in."
   appearsIn: [Episode]
 }
 
@@ -438,19 +441,29 @@ enum Episode {
 
 "A humanoid creature in the Star Wars universe."
 type Human implements Character {
+  "The id of the human."
   id: String!
+  "The name of the human."
   name: String
+  "The friends of the human, or an empty list if they have none."
   friends: [Character]
+  "Which movies they appear in."
   appearsIn: [Episode]
+  "The home planet of the human, or null if unknown."
   homePlanet: String
 }
 
 "A mechanical creature in the Star Wars universe."
 type Droid implements Character {
+  "The id of the droid."
   id: String!
+  "The name of the droid."
   name: String
+  "The friends of the droid, or an empty list if they have none."
   friends: [Character]
+  "Which movies they appear in."
   appearsIn: [Episode]
+  "The primary function of the droid."
   primaryFunction: String
 }
 """
@@ -975,4 +988,4 @@ scalar EmployeeRef
 scalar EmployeeRef
 '''
     }
-}
+}

src/test/groovy/graphql/language/AstPrinterTest.groovy

@@ -472,6 +472,26 @@ type Query {
 
     }
 
+    def "print field descriptions"() {
+        def query = '''type Query {
+  "description"
+  field(
+  "description"
+  a: String): String
+}
+'''
+        def document = parse(query)
+        String output = printAst(document)
+        expect:
+        output == '''type Query {
+  "description"
+  field(
+  "description"
+  a: String): String
+}
+'''
+    }
+
     def "print empty description"() {
         def query = '''
 ""