Fix AstPrinter throws on empty description (graphql-java#2281)

sonallux · web-flow · commit 656f4e35e5d1 · 2021-04-12T09:40:59.000+10:00
Fix graphql-java#2151
diff --git a/src/main/java/graphql/language/AstPrinter.java b/src/main/java/graphql/language/AstPrinter.java
@@ -505,7 +505,7 @@ private String description(Node<?> node) {
             return "";
         }
         String s;
-        boolean startNewLine = description.getContent().charAt(0) == '\n';
+        boolean startNewLine = description.getContent().length() > 0 && description.getContent().charAt(0) == '\n';
         if (description.isMultiLine()) {
             s = "\"\"\"" + (startNewLine ? "" : "\n") + description.getContent() + "\n\"\"\"\n";
         } else {
diff --git a/src/test/groovy/graphql/language/AstPrinterTest.groovy b/src/test/groovy/graphql/language/AstPrinterTest.groovy
@@ -452,6 +452,20 @@ type Query {
 
     }
 
+    def "print empty description"() {
+        def query = '''
+""
+scalar Demo
+'''
+        def document = parse(query)
+        String output = printAst(document)
+
+        expect:
+        output == '''""
+scalar Demo
+'''
+    }
+
     def "print type extensions"() {
         def query = '''
     extend schema {

Original file line number	Diff line number	Diff line change
`@@ -505,7 +505,7 @@ private String description(Node<?> node) {`
`505`	`505`	`return "";`
`506`	`506`	`}`
`507`	`507`	`String s;`
`508`		`- boolean startNewLine = description.getContent().charAt(0) == '\n';`
	`508`	`+ boolean startNewLine = description.getContent().length() > 0 && description.getContent().charAt(0) == '\n';`
`509`	`509`	`if (description.isMultiLine()) {`
`510`	`510`	`s = "\"\"\"" + (startNewLine ? "" : "\n") + description.getContent() + "\n\"\"\"\n";`
`511`	`511`	`} else {`