Improve the way Json.name is fetched for codegen (#1059)

* Improve the way Json.name is fetched for codegen

* Remove the comment for jsonName

* Add a test for json names with quotation marks

* Fix the broken tests

kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/AdapterGenerator.kt

@@ -125,11 +125,7 @@ internal class AdapterGenerator(
           "%T.of(%L)",
           JsonReader.Options::class.asTypeName(),
           nonTransientProperties
-              .map {
+              .map { CodeBlock.of("%S", it.jsonName) }
-                // We manually put in quotes because we know the jsonName is already escaped.
-                val whitespaceSafeName = it.jsonName.replace(" ", "·")
-                CodeBlock.of("\"$whitespaceSafeName\"")
-              }
               .joinToCode(", ")
       )
       .build()
@@ -495,7 +491,7 @@ internal class AdapterGenerator(
     result.addStatement("%N.beginObject()", writerParam)
     nonTransientProperties.forEach { property ->
       // We manually put in quotes because we know the jsonName is already escaped
-      result.addStatement("%N.name(\"%L\")", writerParam, property.jsonName)
+      result.addStatement("%N.name(%S)", writerParam, property.jsonName)
       result.addStatement("%N.toJson(%N, %N.%N)",
           nameAllocator[property.delegateKey], writerParam, valueParam, property.name)
     }

kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/metadata.kt

@@ -48,6 +48,7 @@ import java.lang.annotation.RetentionPolicy
 import java.lang.annotation.Target
 import java.util.TreeSet
 import javax.annotation.processing.Messager
+import javax.lang.model.element.AnnotationMirror
 import javax.lang.model.element.Element
 import javax.lang.model.element.ElementKind
 import javax.lang.model.element.TypeElement
@@ -328,11 +329,13 @@ private fun List<AnnotationSpec>?.qualifiers(elements: Elements): Set<Annotation
   }
 }
 
-/** Gross, but we can't extract values from AnnotationSpecs by member names alone. */
 private fun List<AnnotationSpec>?.jsonName(): String? {
   if (this == null) return null
-  return find { it.className == JSON }?.let {
+  return find { it.className == JSON }?.let { annotation ->
-    it.members[0].toString().removePrefix("name = \"").removeSuffix("\"")
+    val mirror = requireNotNull(annotation.tag<AnnotationMirror>()) {
+      "Could not get the annotation mirror from the annotation spec"
+    }
+    mirror.elementValues.entries.single { it.key.simpleName.contentEquals("name") }.value.value as String
   }
 }
 

kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/codegen/GeneratedAdaptersTest.kt

@@ -87,6 +87,26 @@ class GeneratedAdaptersTest {
   @JsonClass(generateAdapter = true)
   data class JsonAnnotationWithDollarSign(@Json(name = "\$foo") val bar: String)
 
+  @Test
+  fun jsonAnnotationWithQuotationMark() {
+    val adapter = moshi.adapter<JsonAnnotationWithQuotationMark>()
+
+    // Read
+    val json = """{"\"foo\"": "bar"}"""
+
+    val instance = adapter.fromJson(json)!!
+    assertThat(instance.bar).isEqualTo("bar")
+
+    // Write
+    val expectedJson = """{"\"foo\"":"baz"}"""
+
+    assertThat(adapter.toJson(
+        JsonAnnotationWithQuotationMark("baz"))).isEqualTo(expectedJson)
+  }
+
+  @JsonClass(generateAdapter = true)
+  data class JsonAnnotationWithQuotationMark(@Json(name = "\"foo\"") val bar: String)
+
   @Test
   fun defaultValues() {
     val adapter = moshi.adapter<DefaultValues>()