From 3dc17a61f9a05eff6ed71a67a4e2e898435a3c57 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Thu, 4 Apr 2024 17:59:27 +0200
Subject: [PATCH] =?utf8?q?=F0=9F=9A=A7=20Add=20JSON=20filter?=
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---
 .../pterodactylus/rhynodge/filters/JsonFilter.kt   | 28 +++++++++
 .../rhynodge/filters/JsonFilterTest.kt             | 71 ++++++++++++++++++++++
 2 files changed, 99 insertions(+)
 create mode 100644 src/main/kotlin/net/pterodactylus/rhynodge/filters/JsonFilter.kt
 create mode 100644 src/test/java/net/pterodactylus/rhynodge/filters/JsonFilterTest.kt

diff --git a/src/main/kotlin/net/pterodactylus/rhynodge/filters/JsonFilter.kt b/src/main/kotlin/net/pterodactylus/rhynodge/filters/JsonFilter.kt
new file mode 100644
index 0000000..502a002
--- /dev/null
+++ b/src/main/kotlin/net/pterodactylus/rhynodge/filters/JsonFilter.kt
@@ -0,0 +1,28 @@
+package net.pterodactylus.rhynodge.filters
+
+import com.fasterxml.jackson.core.JsonParseException
+import com.fasterxml.jackson.databind.ObjectMapper
+import net.pterodactylus.rhynodge.Filter
+import net.pterodactylus.rhynodge.State
+import net.pterodactylus.rhynodge.states.FailedState
+import net.pterodactylus.rhynodge.states.HttpState
+import net.pterodactylus.rhynodge.states.JsonState
+
+class JsonFilter : Filter {
+
+	override fun filter(state: State): State {
+		if (state is FailedState) {
+			return state
+		}
+		val httpState = state as? HttpState ?: throw IllegalArgumentException("state must be HttpState")
+		val jsonNode = try {
+			objectMapper.readTree(httpState.rawResult())
+		} catch (jsonParseException: JsonParseException) {
+			return FailedState(jsonParseException)
+		}
+		return JsonState(jsonNode)
+	}
+
+}
+
+private val objectMapper = ObjectMapper()
diff --git a/src/test/java/net/pterodactylus/rhynodge/filters/JsonFilterTest.kt b/src/test/java/net/pterodactylus/rhynodge/filters/JsonFilterTest.kt
new file mode 100644
index 0000000..a37990a
--- /dev/null
+++ b/src/test/java/net/pterodactylus/rhynodge/filters/JsonFilterTest.kt
@@ -0,0 +1,71 @@
+package net.pterodactylus.rhynodge.filters
+
+import com.spotify.hamcrest.jackson.JsonMatchers.jsonArray
+import com.spotify.hamcrest.jackson.JsonMatchers.jsonDouble
+import com.spotify.hamcrest.jackson.JsonMatchers.jsonNull
+import com.spotify.hamcrest.jackson.JsonMatchers.jsonObject
+import com.spotify.hamcrest.jackson.JsonMatchers.jsonText
+import net.pterodactylus.rhynodge.Filter
+import net.pterodactylus.rhynodge.states.AbstractState
+import net.pterodactylus.rhynodge.states.FailedState
+import net.pterodactylus.rhynodge.states.HttpState
+import net.pterodactylus.rhynodge.states.JsonState
+import net.pterodactylus.rhynodge.states.StringState
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.Matchers.contains
+import org.hamcrest.Matchers.instanceOf
+import org.junit.Assert
+import org.junit.Assert.assertThrows
+import org.junit.Test
+
+class JsonFilterTest {
+
+	@Test
+	fun `json filter is a filter implementation`() {
+		assertThat(JsonFilter(), instanceOf(Filter::class.java))
+	}
+
+	@Test
+	fun `http state can be turned into json state`() {
+		val httpState = HttpState("", 200, "application/json", "{\n  \"state\": \"foo\",\n  \"list\": [\n    \"value1\",\n    \"value2\"\n  ],\n  \"object\": {\n    \"foo\": \"bar\",\n    \"baz\": null,\n    \"quux\": 1.5\n  }\n}".encodeToByteArray())
+		val jsonState = filter.filter(httpState) as JsonState
+		val jsonNode = jsonState.jsonNode
+		assertThat(
+			jsonNode, jsonObject()
+				.where("state", jsonText("foo"))
+				.where(
+					"list", jsonArray(
+						contains(
+							jsonText("value1"),
+							jsonText("value2")
+						)
+					)
+				)
+				.where(
+					"object", jsonObject()
+						.where("foo", jsonText("bar"))
+						.where("baz", jsonNull())
+						.where("quux", jsonDouble(1.5))
+				)
+		)
+	}
+
+	@Test
+	fun `json filter returns failed state when json can not be parsed`() {
+		val httpState = HttpState("", 200, "application/json", "<json>this is not json</json>".encodeToByteArray())
+		assertThat(filter.filter(httpState), instanceOf(FailedState::class.java))
+	}
+
+	@Test
+	fun `json filter throws exception if given state is not an http state`() {
+		assertThrows(IllegalArgumentException::class.java) { filter.filter(StringState("foo")) }
+	}
+
+	@Test
+	fun `json filter returns a failed state when a failed state is given`() {
+		val newState = filter.filter(FailedState())
+		assertThat(newState, instanceOf(FailedState::class.java))
+	}
+
+	val filter = JsonFilter()
+}
-- 
2.7.4