[#1739] Support sending floats (#1740)

* [#1739] Support sending floats

Required for `FloatFilter`, which needs to be float due to DB layer

* Simplify `parseValueImpl`, use correct coercion hints

server/src/main/kotlin/suwayomi/tachidesk/graphql/server/TachideskGraphQLSchema.kt

@@ -46,6 +46,7 @@ import suwayomi.tachidesk.graphql.queries.UpdateQuery
 import suwayomi.tachidesk.graphql.server.primitives.Cursor
 import suwayomi.tachidesk.graphql.server.primitives.GraphQLCursor
 import suwayomi.tachidesk.graphql.server.primitives.GraphQLDurationAsString
+import suwayomi.tachidesk.graphql.server.primitives.GraphQLFloatAsDouble
 import suwayomi.tachidesk.graphql.server.primitives.GraphQLLongAsString
 import suwayomi.tachidesk.graphql.server.primitives.GraphQLUpload
 import suwayomi.tachidesk.graphql.subscriptions.DownloadSubscription
@@ -64,6 +65,7 @@ class CustomSchemaGeneratorHooks : FlowSubscriptionSchemaGeneratorHooks() {
     override fun willGenerateGraphQLType(type: KType): GraphQLType? =
         when (type.classifier as? KClass<*>) {
             Long::class -> GraphQLLongAsString // encode to string for JS
+            Float::class -> GraphQLFloatAsDouble // encode float as double
             Duration::class -> GraphQLDurationAsString // encode Duration as ISO-8601 string
             Cursor::class -> GraphQLCursor
             UploadedFile::class -> GraphQLUpload

server/src/main/kotlin/suwayomi/tachidesk/graphql/server/primitives/FloatAsDouble.kt

@@ -0,0 +1,132 @@
+package suwayomi.tachidesk.graphql.server.primitives
+
+import graphql.GraphQLContext
+import graphql.execution.CoercedVariables
+import graphql.language.FloatValue
+import graphql.language.Value
+import graphql.scalar.CoercingUtil
+import graphql.schema.Coercing
+import graphql.schema.CoercingParseLiteralException
+import graphql.schema.CoercingParseValueException
+import graphql.schema.CoercingSerializeException
+import graphql.schema.GraphQLScalarType
+import java.util.Locale
+
+val GraphQLFloatAsDouble: GraphQLScalarType =
+    GraphQLScalarType
+        .newScalar()
+        .name(
+            "Float32",
+        ).description("32-bit float aka kotlin.lang.Float")
+        .coercing(GraphqlActualFloatCoercing())
+        .build()
+
+private class GraphqlActualFloatCoercing : Coercing<Float, Double> {
+    private fun toDoubleImpl(input: Any): Double? =
+        when (input) {
+            is Float -> input.toDouble()
+            is Double -> input
+            is Int -> input.toDouble()
+            else -> null
+        }
+
+    private fun parseValueImpl(
+        input: Any,
+        locale: Locale,
+    ): Float =
+        when (input) {
+            is Int -> input.toFloat()
+            is Double -> input.toFloat()
+            else -> throw CoercingParseValueException(
+                CoercingUtil.i18nMsg(
+                    locale,
+                    "Float.unexpectedRawValueType",
+                    CoercingUtil.typeName(input),
+                ),
+            )
+        }
+
+    private fun parseLiteralImpl(
+        input: Any,
+        locale: Locale,
+    ): Float {
+        if (input !is FloatValue) {
+            throw CoercingParseLiteralException(
+                CoercingUtil.i18nMsg(
+                    locale,
+                    "Scalar.unexpectedAstType",
+                    "FloatValue",
+                    CoercingUtil.typeName(input),
+                ),
+            )
+        }
+        return input.value.toFloat()
+    }
+
+    private fun valueToLiteralImpl(input: Any): FloatValue =
+        FloatValue
+            .newFloatValue()
+            .value(
+                toDoubleImpl(input) ?: throw CoercingSerializeException(
+                    CoercingUtil.i18nMsg(
+                        Locale.getDefault(),
+                        "Float.unexpectedRawValueType",
+                        CoercingUtil.typeName(input),
+                    ),
+                ),
+            ).build()
+
+    @Deprecated("")
+    override fun serialize(dataFetcherResult: Any): Double =
+        toDoubleImpl(dataFetcherResult) ?: throw CoercingSerializeException(
+            CoercingUtil.i18nMsg(
+                Locale.getDefault(),
+                "Float.unexpectedRawValueType",
+                CoercingUtil.typeName(dataFetcherResult),
+            ),
+        )
+
+    @Throws(CoercingSerializeException::class)
+    override fun serialize(
+        dataFetcherResult: Any,
+        graphQLContext: GraphQLContext,
+        locale: Locale,
+    ): Double =
+        toDoubleImpl(dataFetcherResult) ?: throw CoercingSerializeException(
+            CoercingUtil.i18nMsg(
+                locale,
+                "Float.unexpectedRawValueType",
+                CoercingUtil.typeName(dataFetcherResult),
+            ),
+        )
+
+    @Deprecated("")
+    override fun parseValue(input: Any): Float = parseValueImpl(input, Locale.getDefault())
+
+    @Throws(CoercingParseValueException::class)
+    override fun parseValue(
+        input: Any,
+        graphQLContext: GraphQLContext,
+        locale: Locale,
+    ): Float = parseValueImpl(input, locale)
+
+    @Deprecated("")
+    override fun parseLiteral(input: Any): Float = parseLiteralImpl(input, Locale.getDefault())
+
+    @Throws(CoercingParseLiteralException::class)
+    override fun parseLiteral(
+        input: Value<*>,
+        variables: CoercedVariables,
+        graphQLContext: GraphQLContext,
+        locale: Locale,
+    ): Float = parseLiteralImpl(input, locale)
+
+    @Deprecated("")
+    override fun valueToLiteral(input: Any): Value<*> = valueToLiteralImpl(input)
+
+    override fun valueToLiteral(
+        input: Any,
+        graphQLContext: GraphQLContext,
+        locale: Locale,
+    ): Value<*> = valueToLiteralImpl(input)
+}