Use map instead of flatMap when parsing

`JSONValue.parse` returns a non-optional `JSONValue`. Unfortunately, because of Swift Magic, Xcode will happily compile when using `flatMap` with a function that returns a non-optional. This can (but doesn't always) result in a EXC_BAD_ACCESS error at runtime. Using `map` here is actually the correct behavior, but should also fix this crash that people were seeing.
thoughtbot · Jan 14, 2015 · 7a522a5 · 7a522a5
1 parent 6a541c2
commit 7a522a5
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Showing 4 changed files with 25 additions and 1 deletion.
diff --git a/Argo.xcodeproj/project.pbxproj b/Argo.xcodeproj/project.pbxproj
@@ -47,6 +47,8 @@
 		F862E0AC1A519D520093B028 /* post_comments.json in Resources */ = {isa = PBXBuildFile; fileRef = EA08313219D5EEF2003B90D7 /* post_comments.json */; };
 		F862E0AD1A519D560093B028 /* types.json in Resources */ = {isa = PBXBuildFile; fileRef = EA08313419D5EFC0003B90D7 /* types.json */; };
 		F862E0AE1A519D5C0093B028 /* types_fail_embedded.json in Resources */ = {isa = PBXBuildFile; fileRef = EA4EAF7219DD96330036AE0D /* types_fail_embedded.json */; };
+		F874B7EA1A66BF52004CCE5E /* root_array.json in Resources */ = {isa = PBXBuildFile; fileRef = F874B7E91A66BF52004CCE5E /* root_array.json */; };
+		F874B7EB1A66C221004CCE5E /* root_array.json in Resources */ = {isa = PBXBuildFile; fileRef = F874B7E91A66BF52004CCE5E /* root_array.json */; };
 		F893355F1A4CE83000B88685 /* Argo.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = F89335541A4CE83000B88685 /* Argo.framework */; };
 		F893356E1A4CE8FC00B88685 /* Argo.h in Headers */ = {isa = PBXBuildFile; fileRef = F893356D1A4CE8FC00B88685 /* Argo.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		F893356F1A4CE8FC00B88685 /* Argo.h in Headers */ = {isa = PBXBuildFile; fileRef = F893356D1A4CE8FC00B88685 /* Argo.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -149,6 +151,7 @@
 		EADADCB11A5DB6F600B180EC /* EquatableSpec.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = EquatableSpec.swift; sourceTree = "<group>"; };
 		F802D4C21A5EE061005E236C /* NSURL.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NSURL.swift; sourceTree = "<group>"; };
 		F802D4C51A5EE2D5005E236C /* url.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = url.json; sourceTree = "<group>"; };
+		F874B7E91A66BF52004CCE5E /* root_array.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = root_array.json; sourceTree = "<group>"; };
 		F89335541A4CE83000B88685 /* Argo.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Argo.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		F893355E1A4CE83000B88685 /* Argo-MacTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = "Argo-MacTests.xctest"; sourceTree = BUILT_PRODUCTS_DIR; };
 		F893356D1A4CE8FC00B88685 /* Argo.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = Argo.h; sourceTree = "<group>"; };
@@ -309,6 +312,7 @@
 				EAD9FB0419D2143A0031E006 /* user_with_email.json */,
 				EAD9FB0819D214AA0031E006 /* user_without_email.json */,
 				F802D4C51A5EE2D5005E236C /* url.json */,
+				F874B7E91A66BF52004CCE5E /* root_array.json */,
 				EAD9FB0919D214AA0031E006 /* TemplateIcon2x.png */,
 				EAD9FB1319D30ED00031E006 /* comment.json */,
 				EAD9FB1519D30F8D0031E006 /* post_no_comments.json */,
@@ -506,6 +510,7 @@
 				EA08313519D5EFC0003B90D7 /* types.json in Resources */,
 				EA4EAF7319DD96330036AE0D /* types_fail_embedded.json in Resources */,
 				EA395DCA1A52FC1400EB607E /* root_object.json in Resources */,
+				F874B7EA1A66BF52004CCE5E /* root_array.json in Resources */,
 				EAD9FB1619D30F8D0031E006 /* post_no_comments.json in Resources */,
 				EA08313319D5EEF2003B90D7 /* post_comments.json in Resources */,
 				EAD9FB0A19D214AA0031E006 /* user_without_email.json in Resources */,
@@ -532,6 +537,7 @@
 				F862E0AD1A519D560093B028 /* types.json in Resources */,
 				F862E0AE1A519D5C0093B028 /* types_fail_embedded.json in Resources */,
 				EA395DCB1A52FC1400EB607E /* root_object.json in Resources */,
+				F874B7EB1A66C221004CCE5E /* root_array.json in Resources */,
 				F8EF75711A4CEC7100BDCC2D /* post_no_comments.json in Resources */,
 				F862E0AC1A519D520093B028 /* post_comments.json in Resources */,
 				F8EF756E1A4CEC7100BDCC2D /* user_without_email.json in Resources */,

diff --git a/Argo/Globals/JSONValue.swift b/Argo/Globals/JSONValue.swift
@@ -19,7 +19,7 @@ public extension JSONValue {
     case let v as [String: AnyObject]:
       let object = reduce(v.keys, JSONDict()) { accum, key in
         let append = curry(Dictionary.appendKey)(accum)(key)
-        return (append <^> v[key] >>- self.parse) ?? append(.JSONNull)
+        return (append <^> (self.parse <^> v[key])) ?? append(.JSONNull)
       }
       return .JSONObject(object)
 

diff --git a/ArgoTests/JSON/root_array.json b/ArgoTests/JSON/root_array.json
@@ -0,0 +1,10 @@
+[
+  {
+    "title": "Foo",
+    "age": 21
+  },
+  {
+    "title": "Bar",
+    "age": 32
+  }
+]
diff --git a/ArgoTests/Tests/ExampleTests.swift b/ArgoTests/Tests/ExampleTests.swift
@@ -29,4 +29,12 @@ class ExampleTests: XCTestCase {
     XCTAssert(url != nil)
     XCTAssert(url?.absoluteString == "http://example.com")
   }
+
+  func testDecodingJSONWithRootArray() {
+    let expected = JSONValue.parse([["title": "Foo", "age": 21], ["title": "Bar", "age": 32]])
+    let json: AnyObject? = JSONFileReader.JSON(fromFile: "root_array")
+    let parsed = json >>- JSONValue.parse
+
+    XCTAssert(.Some(expected) == parsed)
+  }
 }