Limit tests

Author: tom-andersen

firebase-firestore/src/test/java/com/google/firebase/firestore/pipeline/LimitTests.kt

@@ -0,0 +1,169 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//      http://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.google.firebase.firestore.pipeline
+
+import com.google.common.truth.Truth.assertThat
+import com.google.firebase.firestore.RealtimePipelineSource
+import com.google.firebase.firestore.TestUtil
+import com.google.firebase.firestore.model.MutableDocument
+import com.google.firebase.firestore.runPipeline
+import com.google.firebase.firestore.testutil.TestUtilKtx.doc
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.runBlocking
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+internal class LimitTests {
+
+  private val db = TestUtil.firestore()
+
+  private fun createDocs(): List<MutableDocument> {
+    val doc1 = doc("k/a", 1000, mapOf("a" to 1L, "b" to 2L))
+    val doc2 = doc("k/b", 1000, mapOf("a" to 3L, "b" to 4L))
+    val doc3 = doc("k/c", 1000, mapOf("a" to 5L, "b" to 6L))
+    val doc4 = doc("k/d", 1000, mapOf("a" to 7L, "b" to 8L))
+    return listOf(doc1, doc2, doc3, doc4)
+  }
+
+  @Test
+  fun `limit zero`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(0)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).isEmpty()
+  }
+
+  @Test
+  fun `limit zero duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(0).limit(0).limit(0)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).isEmpty()
+  }
+
+  @Test
+  fun `limit one`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(1)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(1)
+  }
+
+  @Test
+  fun `limit one duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(1).limit(1).limit(1)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(1)
+  }
+
+  @Test
+  fun `limit two`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(2)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(2)
+  }
+
+  @Test
+  fun `limit two duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(2).limit(2).limit(2)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(2)
+  }
+
+  @Test
+  fun `limit three`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(3)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(3)
+  }
+
+  @Test
+  fun `limit three duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(3).limit(3).limit(3)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(3)
+  }
+
+  @Test
+  fun `limit four`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(4)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4)
+  }
+
+  @Test
+  fun `limit four duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(4).limit(4).limit(4)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4)
+  }
+
+  @Test
+  fun `limit five`(): Unit = runBlocking {
+    val documents = createDocs() // Only 4 docs created
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(5)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4) // Limited by actual doc count
+  }
+
+  @Test
+  fun `limit five duplicated`(): Unit = runBlocking {
+    val documents = createDocs() // Only 4 docs created
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(5).limit(5).limit(5)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4) // Limited by actual doc count
+  }
+
+  @Test
+  fun `limit max`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline = RealtimePipelineSource(db).collection("k").limit(Int.MAX_VALUE)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4)
+  }
+
+  @Test
+  fun `limit max duplicated`(): Unit = runBlocking {
+    val documents = createDocs()
+    val pipeline =
+      RealtimePipelineSource(db).collection("k").limit(Int.MAX_VALUE).limit(Int.MAX_VALUE).limit(Int.MAX_VALUE)
+
+    val result = runPipeline(db, pipeline, flowOf(*documents.toTypedArray())).toList()
+    assertThat(result).hasSize(4)
+  }
+}