From b3ab7a43c33a6a10ad112fd539e627bfec69d9c5 Mon Sep 17 00:00:00 2001
From: ShaggyDemiurge <i.v.khegay@gmail.com>
Date: Thu, 20 Oct 2022 02:15:17 +0700
Subject: [PATCH] Add count() method support (#72)

---
 core/src/jsMain/kotlin/Index.kt       |  3 +++
 core/src/jsMain/kotlin/ObjectStore.kt |  3 +++
 core/src/jsMain/kotlin/Queryable.kt   |  1 +
 core/src/jsMain/kotlin/Transaction.kt | 10 ++++++++++
 core/src/jsTest/kotlin/Samples.kt     | 10 ++++++++++
 5 files changed, 27 insertions(+)

diff --git a/core/src/jsMain/kotlin/Index.kt b/core/src/jsMain/kotlin/Index.kt
index 26661d5..3579cd1 100644
--- a/core/src/jsMain/kotlin/Index.kt
+++ b/core/src/jsMain/kotlin/Index.kt
@@ -18,4 +18,7 @@ public class Index internal constructor(
 
     override fun requestOpenKeyCursor(query: Key?, direction: Cursor.Direction): Request<IDBCursor?> =
         Request(index.openKeyCursor(query?.toJs(), direction.constant))
+
+    override fun requestCount(query: Key?): Request<Int> =
+        Request(index.count(query?.toJs()))
 }
diff --git a/core/src/jsMain/kotlin/ObjectStore.kt b/core/src/jsMain/kotlin/ObjectStore.kt
index c606537..0fb5aa3 100644
--- a/core/src/jsMain/kotlin/ObjectStore.kt
+++ b/core/src/jsMain/kotlin/ObjectStore.kt
@@ -18,4 +18,7 @@ public class ObjectStore internal constructor(
 
     override fun requestOpenKeyCursor(query: Key?, direction: Cursor.Direction): Request<IDBCursor?> =
         Request(objectStore.openKeyCursor(query?.toJs(), direction.constant))
+
+    override fun requestCount(query: Key?): Request<Int> =
+        Request(objectStore.count(query?.toJs()))
 }
diff --git a/core/src/jsMain/kotlin/Queryable.kt b/core/src/jsMain/kotlin/Queryable.kt
index d6ea731..5130bb1 100644
--- a/core/src/jsMain/kotlin/Queryable.kt
+++ b/core/src/jsMain/kotlin/Queryable.kt
@@ -8,4 +8,5 @@ public sealed class Queryable {
     internal abstract fun requestGetAll(query: Key?): Request<Array<dynamic>>
     internal abstract fun requestOpenCursor(query: Key?, direction: Cursor.Direction): Request<IDBCursorWithValue?>
     internal abstract fun requestOpenKeyCursor(query: Key?, direction: Cursor.Direction): Request<IDBCursor?>
+    internal abstract fun requestCount(query: Key?): Request<Int>
 }
diff --git a/core/src/jsMain/kotlin/Transaction.kt b/core/src/jsMain/kotlin/Transaction.kt
index 4508f0c..578f788 100644
--- a/core/src/jsMain/kotlin/Transaction.kt
+++ b/core/src/jsMain/kotlin/Transaction.kt
@@ -97,6 +97,16 @@ public open class Transaction internal constructor(
         }
     }
 
+    public suspend fun Queryable.count(query: Key? = null): Int {
+        val request = requestCount(query).request
+        return request.onNextEvent("success", "error") { event ->
+            when (event.type) {
+                "error" -> throw ErrorEventException(event)
+                else -> request.result
+            }
+        }
+    }
+
     public fun ObjectStore.index(name: String): Index =
         Index(objectStore.index(name))
 }
diff --git a/core/src/jsTest/kotlin/Samples.kt b/core/src/jsTest/kotlin/Samples.kt
index 7f40d22..b098e00 100644
--- a/core/src/jsTest/kotlin/Samples.kt
+++ b/core/src/jsTest/kotlin/Samples.kt
@@ -58,5 +58,15 @@ class Samples {
                 .first { it.age < 32 }
         }
         assertEquals("Charlie", charlie.name)
+
+        val count = database.transaction("customers") {
+            objectStore("customers").count()
+        }
+        assertEquals(4, count)
+
+        val countBelowThirtyTwo = database.transaction("customers") {
+            objectStore("customers").index("age").count(upperBound(32))
+        }
+        assertEquals(2, countBelowThirtyTwo)
     }
 }