feat: add GraphQLContext extension functions (ExpediaGroup#1369)

* feat: add GraphQLContext extension functions

* feat: add ktDocs

Co-authored-by: samvazquez <[email protected]>

Author: samuelAndalon

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/execution/FunctionDataFetcher.kt

@@ -16,6 +16,7 @@
 
 package com.expediagroup.graphql.generator.execution
 
+import com.expediagroup.graphql.generator.extensions.getOrDefault
 import com.expediagroup.graphql.generator.internal.extensions.getJavaClass
 import com.expediagroup.graphql.generator.internal.extensions.getName
 import com.expediagroup.graphql.generator.internal.extensions.getTypeOfFirstArgument
@@ -83,11 +84,10 @@ open class FunctionDataFetcher(
      * in a value for this optional parameter. This allows for the default Kotlin values to be used if no mapping is added.
      * You can override this behaviour by providing a value for a specific [KParameter] when [mapParameterToValue] is called.
      */
-    protected open fun getParameters(fn: KFunction<*>, environment: DataFetchingEnvironment): Map<KParameter, Any?> {
-        return fn.valueParameters
+    protected open fun getParameters(fn: KFunction<*>, environment: DataFetchingEnvironment): Map<KParameter, Any?> =
+        fn.valueParameters
             .mapNotNull { mapParameterToValue(it, environment) }
             .toMap()
-    }
 
     /**
      * Retrieves the provided parameter value in the operation input to pass to the function to execute.
@@ -168,26 +168,22 @@ open class FunctionDataFetcher(
     protected open fun runSuspendingFunction(
         environment: DataFetchingEnvironment,
         parameterValues: Map<KParameter, Any?>
-    ): CompletableFuture<Any?> {
-        val scope = environment.graphQlContext.getOrDefault(CoroutineScope::class, CoroutineScope(EmptyCoroutineContext))
-        return scope.future {
+    ): CompletableFuture<Any?> =
+        environment.graphQlContext.getOrDefault(CoroutineScope(EmptyCoroutineContext)).future {
             try {
                 fn.callSuspendBy(parameterValues)
             } catch (exception: InvocationTargetException) {
                 throw exception.cause ?: exception
             }
         }
-    }
 
     /**
      * Once all parameters values are properly converted, this function will be called to run a simple blocking function.
      * If you need to override the exception handling you can override this method.
      */
-    protected open fun runBlockingFunction(parameterValues: Map<KParameter, Any?>): Any? {
-        try {
-            return fn.callBy(parameterValues)
-        } catch (exception: InvocationTargetException) {
-            throw exception.cause ?: exception
-        }
+    protected open fun runBlockingFunction(parameterValues: Map<KParameter, Any?>): Any? = try {
+        fn.callBy(parameterValues)
+    } catch (exception: InvocationTargetException) {
+        throw exception.cause ?: exception
     }
 }

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/GraphQLContextExtensions.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2022 Expedia, Inc
+ *
+ * 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
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.expediagroup.graphql.generator.extensions
+
+import graphql.GraphQLContext
+
+/**
+ * Returns a value in the context by KClass key
+ * @return a value or null
+ */
+inline fun <reified T> GraphQLContext.get(): T? = get(T::class)
+
+/**
+ * Returns a value in the context by KClass key
+ * @param defaultValue the default value to use if there is no KClass key entry
+ * @return a value or default value
+ */
+inline fun <reified T> GraphQLContext.getOrDefault(defaultValue: T): T = getOrDefault(T::class, defaultValue)
+
+/**
+ * Returns a value in the context by KClass key
+ * @param defaultValue function to invoke if there is no KClass key entry
+ * @return a value or result of [defaultValue] function
+ */
+inline fun <reified T> GraphQLContext.getOrElse(defaultValue: () -> T): T = get(T::class) ?: defaultValue.invoke()

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/GraphQLSchemaExtensions.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Expedia, Inc
+ * Copyright 2022 Expedia, Inc
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/graphqlTypeExtensions.kt renamed to generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/GraphqlTypeExtensions.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Expedia, Inc
+ * Copyright 2022 Expedia, Inc
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.