feat(tags): add api to fetch posts by tags and a utility class Tags

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

api/src/main/kotlin/dev/msfjarvis/claw/api/LobstersApi.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2021-2022 Harsh Shandilya.
+ * Copyright © 2021-2023 Harsh Shandilya.
  * Use of this source code is governed by an MIT-style
  * license that can be found in the LICENSE file or at
  * https://opensource.org/licenses/MIT.
@@ -7,6 +7,7 @@
 package dev.msfjarvis.claw.api
 
 import com.slack.eithernet.ApiResult
+import dev.msfjarvis.claw.api.util.Tags
 import dev.msfjarvis.claw.model.LobstersPost
 import dev.msfjarvis.claw.model.LobstersPostDetails
 import dev.msfjarvis.claw.model.User
@@ -29,6 +30,12 @@ interface LobstersApi {
   @GET("u/{username}.json")
   suspend fun getUser(@Path("username") username: String): ApiResult<User, Unit>
 
+  @GET("t/{tags}.json")
+  suspend fun getPostsByTags(
+    @Path("tags") tag: Tags,
+    @Query("page") page: Int,
+  ): ApiResult<List<LobstersPost>, Unit>
+
   companion object {
     const val BASE_URL = "https://lobste.rs"
   }

api/src/main/kotlin/dev/msfjarvis/claw/api/util/Tags.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright © 2023 Harsh Shandilya.
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+package dev.msfjarvis.claw.api.util
+
+class Tags {
+  private var tags: MutableList<String> = emptyList<String>().toMutableList()
+
+  fun addTag(tag: String) {
+    this.tags.add(tag)
+  }
+
+  fun removeTag(tag: String) {
+    this.tags.remove(tag)
+  }
+
+  override fun toString(): String {
+    return tags.joinToString(",")
+  }
+}

api/src/test/kotlin/dev/msfjarvis/claw/api/ApiTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2022 Harsh Shandilya.
+ * Copyright © 2022-2023 Harsh Shandilya.
  * Use of this source code is governed by an MIT-style
  * license that can be found in the LICENSE file or at
  * https://opensource.org/licenses/MIT.
@@ -8,6 +8,7 @@ package dev.msfjarvis.claw.api
 
 import com.slack.eithernet.ApiResult.Success
 import com.slack.eithernet.test.newEitherNetController
+import dev.msfjarvis.claw.api.util.Tags
 import dev.msfjarvis.claw.model.LobstersPost
 import dev.msfjarvis.claw.model.LobstersPostDetails
 import dev.msfjarvis.claw.model.User
@@ -46,5 +47,24 @@ class ApiTest : FunSpec() {
       user.shouldBeTypeOf<Success<User>>()
       user.value.username shouldBe "msfjarvis"
     }
+
+    test("get posts by single tag") {
+      var tags = Tags()
+      tags.addTag("meta")
+      val posts = api.getPostsByTags(tags, 1)
+      posts.shouldBeTypeOf<Success<List<LobstersPost>>>()
+      posts.value shouldHaveSize 25
+      posts.value[0].tags.contains("meta")
+    }
+
+    test("get posts by multiple tags") {
+      var tags = Tags()
+      tags.addTag("programming")
+      tags.addTag("rust")
+      val posts = api.getPostsByTags(tags, 1)
+      posts.shouldBeTypeOf<Success<List<LobstersPost>>>()
+      posts.value shouldHaveSize 25
+      posts.value[0].tags.contains("programming") or posts.value[0].tags.contains("rust")
+    }
   }
 }

api/src/test/kotlin/dev/msfjarvis/claw/api/ApiWrapper.kt

@@ -28,6 +28,9 @@ class ApiWrapper(controller: EitherNetController<LobstersApi>) {
   private val postDetails: LobstersPostDetails =
     json.decodeFromString(getJson("post_details_tdfoqh.json"))
   private val user: User = json.decodeFromString(getJson("msfjarvis.json"))
+  private val metaPosts: List<LobstersPost> = json.decodeFromString(getJson("meta.json"))
+  private val programmingRustPosts: List<LobstersPost> =
+    json.decodeFromString(getJson("programming_rust.json"))
 
   val api = controller.api
 
@@ -36,5 +39,7 @@ class ApiWrapper(controller: EitherNetController<LobstersApi>) {
     controller.enqueue(LobstersApi::getHottestPosts) { success(hottest) }
     controller.enqueue(LobstersApi::getPostDetails) { success(postDetails) }
     controller.enqueue(LobstersApi::getUser) { success(user) }
+    controller.enqueue(LobstersApi::getPostsByTags) { success(metaPosts) }
+    controller.enqueue(LobstersApi::getPostsByTags) { success(programmingRustPosts) }
   }
 }