From 168a848f101c4b05198006ff25189b6a52651eac Mon Sep 17 00:00:00 2001
From: Keijo Kapp <keijo.kapp@gmail.com>
Date: Thu, 9 May 2024 12:43:50 +0300
Subject: [PATCH 1/2] Fix typings of `at` methods

---
 lib/database.ts | 27 ++++++++++++++++++++-------
 lib/subspace.ts | 26 +++++++++++++++++++++-----
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/lib/database.ts b/lib/database.ts
index 41afec6..214de05 100644
--- a/lib/database.ts
+++ b/lib/database.ts
@@ -43,15 +43,28 @@ export default class Database<KeyIn = NativeValue, KeyOut = Buffer, ValIn = Nati
   // convenience and backwards compatibility.
   /** Create a shallow reference to the database at a specified subspace */
   at<CKI, CKO, CVI, CVO>(hasSubspace: GetSubspace<CKI, CKO, CVI, CVO>): Database<CKI, CKO, CVI, CVO>
-  /** Create a shallow reference to the database at the subspace of another database reference */
-  // at<CKI = KeyIn, CKO = KeyOut, CVI = ValIn, CVO = ValOut>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>): Database<CKI, CKO, CVI, CVO>
-
-  at(prefix: KeyIn | null): Database<KeyIn, KeyOut, ValIn, ValOut>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>): Database<CKI, CKO, ValIn, ValOut>;
+  at(prefix: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Database<KeyIn, KeyOut, ValIn, ValOut>;
+  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Database<CKI, CKO, ValIn, ValOut>;
   at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Database<KeyIn, KeyOut, CVI, CVO>;
   at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Database<CKI, CKO, CVI, CVO>;
-
-  at<CKI, CKO, CVI, CVO>(prefixOrSubspace: GetSubspace<CKI, CKO, CVI, CVO> | KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>): Database<CKI, CKO, CVI, CVO> {
+  at<CKI, CKO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
+    | Database<KeyIn, KeyOut, ValIn, ValOut>
+    | Database<CKI, CKO, ValIn, ValOut>;
+  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
+    | Database<KeyIn, KeyOut, ValIn, ValOut>
+    | Database<KeyIn, KeyOut, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
+    | Database<KeyIn, KeyOut, CVI, CVO>
+    | Database<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+    | Database<CKI, CKO, ValIn, ValOut>
+    | Database<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+    | Database<KeyIn, KeyOut, ValIn, ValOut>
+    | Database<CKI, CKO, ValIn, ValOut>
+    | Database<KeyIn, KeyOut, CVI, CVO>
+    | Database<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefixOrSubspace: GetSubspace<CKI, CKO, CVI, CVO> | KeyIn | null, keyXf?: Transformer<unknown, unknown>, valueXf?: Transformer<unknown, unknown>) {
     if (isGetSubspace(prefixOrSubspace)) return new Database(this._db, prefixOrSubspace.getSubspace())
     else return new Database(this._db, this.subspace.at(prefixOrSubspace, keyXf, valueXf))
   }
diff --git a/lib/subspace.ts b/lib/subspace.ts
index eb52e0c..9c75507 100644
--- a/lib/subspace.ts
+++ b/lib/subspace.ts
@@ -41,12 +41,28 @@ export default class Subspace<KeyIn = NativeValue, KeyOut = Buffer, ValIn = Nati
   // legit all the variants. Typescript can probably infer using less than this,
   // but I honestly don't trust it not to land with any or unknown or something
   // in some of the derived types
-  at(prefix: KeyIn | null): Subspace<KeyIn, KeyOut, ValIn, ValOut>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>): Subspace<CKI, CKO, ValIn, ValOut>;
+  at(prefix: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Subspace<KeyIn, KeyOut, ValIn, ValOut>;
+  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Subspace<CKI, CKO, ValIn, ValOut>;
   at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Subspace<KeyIn, KeyOut, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>): Subspace<CKI, CKO, CVI, CVO>;
-  // ***
-  at(prefix: KeyIn | null, keyXf: Transformer<any, any> = this.keyXf, valueXf: Transformer<any, any> = this.valueXf) {
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Subspace<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
+    | Subspace<KeyIn, KeyOut, ValIn, ValOut>
+    | Subspace<CKI, CKO, ValIn, ValOut>;
+  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
+    | Subspace<KeyIn, KeyOut, ValIn, ValOut>
+    | Subspace<KeyIn, KeyOut, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
+    | Subspace<KeyIn, KeyOut, CVI, CVO>
+    | Subspace<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+    | Subspace<CKI, CKO, ValIn, ValOut>
+    | Subspace<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+    | Subspace<KeyIn, KeyOut, ValIn, ValOut>
+    | Subspace<CKI, CKO, ValIn, ValOut>
+    | Subspace<KeyIn, KeyOut, CVI, CVO>
+    | Subspace<CKI, CKO, CVI, CVO>;
+  at(prefix: KeyIn | null, keyXf: Transformer<unknown, unknown> = this.keyXf, valueXf: Transformer<unknown, unknown> = this.valueXf) {
     const _prefix = prefix == null ? null : this.keyXf.pack(prefix)
     return new Subspace(concatPrefix(this.prefix, _prefix), keyXf, valueXf)
   }

From cd6e04443a36d1129494bff99472c28167d946c5 Mon Sep 17 00:00:00 2001
From: Keijo Kapp <keijo.kapp@gmail.com>
Date: Thu, 9 May 2024 12:44:33 +0300
Subject: [PATCH 2/2] Made subspacing methods consistent

---
 lib/database.ts | 44 ++++++++++++++++++++++++++------------------
 lib/subspace.ts | 39 ++++++++++++++++++++++++---------------
 2 files changed, 50 insertions(+), 33 deletions(-)

diff --git a/lib/database.ts b/lib/database.ts
index 214de05..8289fdd 100644
--- a/lib/database.ts
+++ b/lib/database.ts
@@ -1,6 +1,6 @@
 import * as fdb from './native'
 import Transaction, { RangeOptions, Watch } from './transaction'
-import {Transformer, defaultTransformer} from './transformer'
+import {Transformer} from './transformer'
 import {NativeValue} from './native'
 import {KeySelector} from './keySelector'
 import Subspace, { root, GetSubspace, isGetSubspace } from './subspace'
@@ -43,40 +43,48 @@ export default class Database<KeyIn = NativeValue, KeyOut = Buffer, ValIn = Nati
   // convenience and backwards compatibility.
   /** Create a shallow reference to the database at a specified subspace */
   at<CKI, CKO, CVI, CVO>(hasSubspace: GetSubspace<CKI, CKO, CVI, CVO>): Database<CKI, CKO, CVI, CVO>
-  at(prefix: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Database<KeyIn, KeyOut, ValIn, ValOut>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Database<CKI, CKO, ValIn, ValOut>;
-  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Database<KeyIn, KeyOut, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Database<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
+  at(prefix?: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Database<KeyIn, KeyOut, ValIn, ValOut>;
+  at<CKI, CKO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Database<CKI, CKO, ValIn, ValOut>;
+  at<CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Database<KeyIn, KeyOut, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Database<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO>(prefix: KeyIn | null | undefined, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
     | Database<KeyIn, KeyOut, ValIn, ValOut>
     | Database<CKI, CKO, ValIn, ValOut>;
-  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
+  at<CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
     | Database<KeyIn, KeyOut, ValIn, ValOut>
     | Database<KeyIn, KeyOut, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
     | Database<KeyIn, KeyOut, CVI, CVO>
     | Database<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
     | Database<CKI, CKO, ValIn, ValOut>
     | Database<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix?: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
     | Database<KeyIn, KeyOut, ValIn, ValOut>
     | Database<CKI, CKO, ValIn, ValOut>
     | Database<KeyIn, KeyOut, CVI, CVO>
     | Database<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefixOrSubspace: GetSubspace<CKI, CKO, CVI, CVO> | KeyIn | null, keyXf?: Transformer<unknown, unknown>, valueXf?: Transformer<unknown, unknown>) {
+  at<CKI, CKO, CVI, CVO>(prefixOrSubspace?: GetSubspace<CKI, CKO, CVI, CVO> | KeyIn | null, keyXf?: Transformer<unknown, unknown>, valueXf?: Transformer<unknown, unknown>) {
     if (isGetSubspace(prefixOrSubspace)) return new Database(this._db, prefixOrSubspace.getSubspace())
     else return new Database(this._db, this.subspace.at(prefixOrSubspace, keyXf, valueXf))
   }
 
-  withKeyEncoding<ChildKeyIn, ChildKeyOut>(keyXf: Transformer<ChildKeyIn, ChildKeyOut>): Database<ChildKeyIn, ChildKeyOut, ValIn, ValOut>
-  withKeyEncoding<NativeValue, Buffer>(): Database<NativeValue, Buffer, ValIn, ValOut>
-  withKeyEncoding<ChildKeyIn, ChildKeyOut>(keyXf: Transformer<any, any> = defaultTransformer): Database<ChildKeyIn, ChildKeyOut, ValIn, ValOut> {
-    return new Database(this._db, this.subspace.at(null, keyXf))
+  withKeyEncoding(keyXf?: undefined): Database<NativeValue, Buffer, ValIn, ValOut>
+  withKeyEncoding<CKI, CKO>(keyXf: Transformer<CKI, CKO>): Database<CKI, CKO, ValIn, ValOut>
+  withKeyEncoding<CKI, CKO>(keyXf?: Transformer<CKI, CKO>):
+    | Database<NativeValue, Buffer, ValIn, ValOut>
+    | Database<CKI, CKO, ValIn, ValOut>
+  withKeyEncoding(keyXf?: Transformer<unknown, unknown>) {
+    return new Database(this._db, this.subspace.withKeyEncoding(keyXf))
   }
-  
-  withValueEncoding<ChildValIn, ChildValOut>(valXf: Transformer<ChildValIn, ChildValOut>): Database<KeyIn, KeyOut, ChildValIn, ChildValOut> {
-    return new Database(this._db, this.subspace.at(null, undefined /* inherit */, valXf))
+
+  withValueEncoding(valueXf?: undefined): Database<KeyIn, KeyOut, NativeValue, Buffer>
+  withValueEncoding<CVI, CVO>(valueXf: Transformer<CVI, CVO>): Database<KeyIn, KeyOut, CVI, CVO>
+  withValueEncoding<CVI, CVO>(valueXf?: Transformer<CVI, CVO>):
+    | Database<KeyIn, KeyOut, NativeValue, Buffer>
+    | Database<KeyIn, KeyOut, CVI, CVO>
+  withValueEncoding(valueXf?: Transformer<unknown, unknown>) {
+    return new Database(this._db, this.subspace.withValueEncoding(valueXf))
   }
 
   // This is the API you want to use for non-trivial transactions.
diff --git a/lib/subspace.ts b/lib/subspace.ts
index 9c75507..d1e44f5 100644
--- a/lib/subspace.ts
+++ b/lib/subspace.ts
@@ -41,28 +41,28 @@ export default class Subspace<KeyIn = NativeValue, KeyOut = Buffer, ValIn = Nati
   // legit all the variants. Typescript can probably infer using less than this,
   // but I honestly don't trust it not to land with any or unknown or something
   // in some of the derived types
-  at(prefix: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Subspace<KeyIn, KeyOut, ValIn, ValOut>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Subspace<CKI, CKO, ValIn, ValOut>;
-  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Subspace<KeyIn, KeyOut, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Subspace<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
+  at(prefix?: KeyIn | null, keyXf?: undefined, valueXf?: undefined): Subspace<KeyIn, KeyOut, ValIn, ValOut>;
+  at<CKI, CKO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf?: undefined): Subspace<CKI, CKO, ValIn, ValOut>;
+  at<CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: undefined, valueXf: Transformer<CVI, CVO>): Subspace<KeyIn, KeyOut, CVI, CVO>;
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf: Transformer<CVI, CVO>): Subspace<CKI, CKO, CVI, CVO>;
+  at<CKI, CKO>(prefix: KeyIn | null | undefined, keyXf?: Transformer<CKI, CKO>, valueXf?: undefined):
     | Subspace<KeyIn, KeyOut, ValIn, ValOut>
     | Subspace<CKI, CKO, ValIn, ValOut>;
-  at<CVI, CVO>(prefix: KeyIn | null, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
+  at<CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: undefined, valueXf?: Transformer<CVI, CVO>):
     | Subspace<KeyIn, KeyOut, ValIn, ValOut>
     | Subspace<KeyIn, KeyOut, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO> | undefined, valueXf: Transformer<CVI, CVO>):
     | Subspace<KeyIn, KeyOut, CVI, CVO>
     | Subspace<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null | undefined, keyXf: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
     | Subspace<CKI, CKO, ValIn, ValOut>
     | Subspace<CKI, CKO, CVI, CVO>;
-  at<CKI, CKO, CVI, CVO>(prefix: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
+  at<CKI, CKO, CVI, CVO>(prefix?: KeyIn | null, keyXf?: Transformer<CKI, CKO>, valueXf?: Transformer<CVI, CVO>):
     | Subspace<KeyIn, KeyOut, ValIn, ValOut>
     | Subspace<CKI, CKO, ValIn, ValOut>
     | Subspace<KeyIn, KeyOut, CVI, CVO>
     | Subspace<CKI, CKO, CVI, CVO>;
-  at(prefix: KeyIn | null, keyXf: Transformer<unknown, unknown> = this.keyXf, valueXf: Transformer<unknown, unknown> = this.valueXf) {
+  at(prefix?: KeyIn | null, keyXf: Transformer<unknown, unknown> = this.keyXf, valueXf: Transformer<unknown, unknown> = this.valueXf) {
     const _prefix = prefix == null ? null : this.keyXf.pack(prefix)
     return new Subspace(concatPrefix(this.prefix, _prefix), keyXf, valueXf)
   }
@@ -72,13 +72,22 @@ export default class Subspace<KeyIn = NativeValue, KeyOut = Buffer, ValIn = Nati
     return new Subspace(concatPrefix(this.prefix, prefix), this.keyXf, this.valueXf)
   }
 
-
-  withKeyEncoding<CKI, CKO>(keyXf: Transformer<CKI, CKO>): Subspace<CKI, CKO, ValIn, ValOut> {
+  withKeyEncoding(keyXf?: undefined): Subspace<NativeValue, Buffer, ValIn, ValOut>
+  withKeyEncoding<CKI, CKO>(keyXf: Transformer<CKI, CKO>): Subspace<CKI, CKO, ValIn, ValOut>
+  withKeyEncoding<CKI, CKO>(keyXf?: Transformer<CKI, CKO>):
+    | Subspace<NativeValue, Buffer, ValIn, ValOut>
+    | Subspace<CKI, CKO, ValIn, ValOut>
+  withKeyEncoding(keyXf?: Transformer<unknown, unknown>) {
     return new Subspace(this.prefix, keyXf, this.valueXf)
   }
-  
-  withValueEncoding<CVI, CVO>(valXf: Transformer<CVI, CVO>): Subspace<KeyIn, KeyOut, CVI, CVO> {
-    return new Subspace(this.prefix, this.keyXf, valXf)
+
+  withValueEncoding(valueXf?: undefined): Subspace<KeyIn, KeyOut, NativeValue, Buffer>
+  withValueEncoding<CVI, CVO>(valueXf: Transformer<CVI, CVO>): Subspace<KeyIn, KeyOut, CVI, CVO>
+  withValueEncoding<CVI, CVO>(valueXf?: Transformer<CVI, CVO>):
+    | Subspace<KeyIn, KeyOut, NativeValue, Buffer>
+    | Subspace<KeyIn, KeyOut, CVI, CVO>
+  withValueEncoding(valueXf?: Transformer<unknown, unknown>) {
+    return new Subspace(this.prefix, this.keyXf, valueXf)
   }
 
   // GetSubspace implementation