Fix expansion of @RequestParam empty lists (OpenFeign#1200)

darrenfoong · web-flow · commit dc081d136d4c · 2020-04-19T16:09:29.000-04:00
* Add list tests to QueryTemplateTest

* Make expandIterable() return empty string if unresolved

* Rename new tests to fit existing tests

* Format code

* Fix newlines
diff --git a/core/src/main/java/feign/template/Expressions.java b/core/src/main/java/feign/template/Expressions.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -152,11 +152,6 @@ private String expandIterable(Iterable<?> values) {
         }
       }
 
-      if (result.length() == 0) {
-        /* completely unresolved */
-        return null;
-      }
-
       /* return the expanded value */
       return result.toString();
     }
diff --git a/core/src/test/java/feign/template/QueryTemplateTest.java b/core/src/test/java/feign/template/QueryTemplateTest.java
@@ -30,6 +30,23 @@ public void templateToQueryString() {
     assertThat(template.toString()).isEqualToIgnoringCase("name=Bob&name=James&name=Jason");
   }
 
+  @Test
+  public void expandEmptyCollection() {
+    QueryTemplate template =
+        QueryTemplate.create("people", Collections.singletonList("{people}"), Util.UTF_8);
+    String expanded = template.expand(Collections.singletonMap("people", Collections.emptyList()));
+    assertThat(expanded).isEqualToIgnoringCase("people=");
+  }
+
+  @Test
+  public void expandCollection() {
+    QueryTemplate template =
+        QueryTemplate.create("people", Collections.singletonList("{people}"), Util.UTF_8);
+    String expanded =
+        template.expand(Collections.singletonMap("people", Arrays.asList("Bob", "James", "Jason")));
+    assertThat(expanded).isEqualToIgnoringCase("people=Bob&people=James&people=Jason");
+  }
+
   @Test
   public void expandCollectionWithBlanks() {
     QueryTemplate template =

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`/**`
`2`		`- * Copyright 2012-2019 The Feign Authors`
	`2`	`+ * Copyright 2012-2020 The Feign Authors`
`3`	`3`	`*`
`4`	`4`	`* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except`
`5`	`5`	`* in compliance with the License. You may obtain a copy of the License at`
`@@ -152,11 +152,6 @@ private String expandIterable(Iterable<?> values) {`
`152`	`152`	`}`
`153`	`153`	`}`
`154`	`154`
`155`		`- if (result.length() == 0) {`
`156`		`- /* completely unresolved */`
`157`		`- return null;`
`158`		`- }`
`159`		`-`
`160`	`155`	`/* return the expanded value */`
`161`	`156`	`return result.toString();`
`162`	`157`	`}`