refactor(experimental): rename getScalarEnumCodec to getEnumCodec (#2383

)

Now that "Data Enum" is called "Discriminated Union", "Scalar Enum" can also be appropriately renamed as "Enum".

See #2296.

.changeset/loud-otters-pull.md

@@ -0,0 +1,8 @@
+---
+'@solana/codecs-data-structures': patch
+'@solana/codecs-core': patch
+'@solana/codecs': patch
+'@solana/errors': patch
+---
+
+`getScalarEnumCodec` is now called `getEnumCodec`

packages/codecs-core/README.md

@@ -43,7 +43,7 @@ There is a significant library of composable codecs at your disposal, enabling y
 
 -   [`@solana/codecs-numbers`](https://github.com/solana-labs/solana-web3.js/tree/master/packages/codecs-numbers) for number codecs.
 -   [`@solana/codecs-strings`](https://github.com/solana-labs/solana-web3.js/tree/master/packages/codecs-strings) for string codecs.
--   [`@solana/codecs-data-structures`](https://github.com/solana-labs/solana-web3.js/tree/master/packages/codecs-data-structures) for many data structure codecs such as objects, arrays, tuples, sets, maps, scalar enums, discriminated unions, booleans, etc.
+-   [`@solana/codecs-data-structures`](https://github.com/solana-labs/solana-web3.js/tree/master/packages/codecs-data-structures) for many data structure codecs such as objects, arrays, tuples, sets, maps, enums, discriminated unions, booleans, etc.
 -   [`@solana/options`](https://github.com/solana-labs/solana-web3.js/tree/master/packages/options) for a Rust-like `Option` type and associated codec.
 
 You may also be interested in some of the helpers of this `@solana/codecs-core` library such as `mapCodec`, `fixCodec` or `reverseCodec` that create new codecs from existing ones.

packages/codecs-data-structures/README.md

@@ -179,9 +179,9 @@ const bytes = personEncoder.encode({ name: 'alice', age: 42 });
 const person = personDecoder.decode(bytes);
 ```
 
-## Scalar enum codec
+## Enum codec
 
-The `getScalarEnumCodec` function accepts a JavaScript enum constructor and returns a codec for encoding and decoding values of that enum.
+The `getEnumCodec` function accepts a JavaScript enum constructor and returns a codec for encoding and decoding values of that enum.
 
 ```ts
 enum Direction {
@@ -191,11 +191,11 @@ enum Direction {
     Down,
 }
 
-const bytes = getScalarEnumCodec(Direction).encode(Direction.Left);
-const direction = getScalarEnumCodec(Direction).decode(bytes);
+const bytes = getEnumCodec(Direction).encode(Direction.Left);
+const direction = getEnumCodec(Direction).decode(bytes);
 ```
 
-When encoding a scalar enum, you may pass the value as an enum value, as a number or even as a string by passing the variant’s name.
+When encoding an enum, you may pass the value as an enum value, as a number or even as a string by passing the variant’s name.
 
 ```ts
 enum Direction {
@@ -205,23 +205,23 @@ enum Direction {
     Down,
 }
 
-getScalarEnumCodec(Direction).encode(Direction.Left); // 0x00
-getScalarEnumCodec(Direction).encode(Direction.Right); // 0x01
-getScalarEnumCodec(Direction).encode(0); // 0x00
-getScalarEnumCodec(Direction).encode(1); // 0x01
-getScalarEnumCodec(Direction).encode('Left'); // 0x00
-getScalarEnumCodec(Direction).encode('Right'); // 0x01
+getEnumCodec(Direction).encode(Direction.Left); // 0x00
+getEnumCodec(Direction).encode(Direction.Right); // 0x01
+getEnumCodec(Direction).encode(0); // 0x00
+getEnumCodec(Direction).encode(1); // 0x01
+getEnumCodec(Direction).encode('Left'); // 0x00
+getEnumCodec(Direction).encode('Right'); // 0x01
 ```
 
 As you can see, by default, a `u8` number is being used to store the enum value. However, a number codec may be passed as the `size` option to configure that behaviour.
 
 ```ts
-const u32DirectionCodec = getScalarEnumCodec(Direction, { size: getU32Codec() });
+const u32DirectionCodec = getEnumCodec(Direction, { size: getU32Codec() });
 u32DirectionCodec.encode(Direction.Left); // 0x00000000
 u32DirectionCodec.encode(Direction.Right); // 0x01000000
 ```
 
-Note that if you provide a string enum — e.g. `enum Direction { Left = 'LEFT' }` — to the `getScalarEnumCodec` function, it will only store the index of the variant. However, the string value may be used to encode that index.
+Note that if you provide a string enum — e.g. `enum Direction { Left = 'LEFT' }` — to the `getEnumCodec` function, it will only store the index of the variant. However, the string value may be used to encode that index.
 
 ```ts
 enum Direction {
@@ -231,16 +231,16 @@ enum Direction {
     Down = 'DOWN',
 }
 
-getScalarEnumCodec(Direction).encode(Direction.Right); // 0x01
-getScalarEnumCodec(Direction).encode('Right' as Direction); // 0x01
-getScalarEnumCodec(Direction).encode('RIGHT'); // 0x01
+getEnumCodec(Direction).encode(Direction.Right); // 0x01
+getEnumCodec(Direction).encode('Right' as Direction); // 0x01
+getEnumCodec(Direction).encode('RIGHT'); // 0x01
 ```
 
-Separate `getScalarEnumEncoder` and `getScalarEnumDecoder` functions are also available.
+Separate `getEnumEncoder` and `getEnumDecoder` functions are also available.
 
 ```ts
-const bytes = getScalarEnumEncoder(Direction).encode(Direction.Left);
-const direction = getScalarEnumDecoder(Direction).decode(bytes);
+const bytes = getEnumEncoder(Direction).encode(Direction.Left);
+const direction = getEnumDecoder(Direction).decode(bytes);
 ```
 
 ## Discriminated union codec

packages/codecs-data-structures/src/__tests__/enum-test.ts

@@ -0,0 +1,159 @@
+import { getU32Codec, getU64Codec } from '@solana/codecs-numbers';
+import {
+    SOLANA_ERROR__CODECS__ENUM_DISCRIMINATOR_OUT_OF_RANGE,
+    SOLANA_ERROR__CODECS__INVALID_ENUM_VARIANT,
+    SolanaError,
+} from '@solana/errors';
+
+import { getEnumCodec } from '../enum';
+import { b } from './__setup__';
+
+describe('getEnumCodec', () => {
+    const u32 = getU32Codec;
+    const u64 = getU64Codec;
+
+    enum Empty {}
+    enum Feedback {
+        BAD,
+        GOOD,
+    }
+    enum Direction {
+        UP = 'Up',
+        DOWN = 'Down',
+        LEFT = 'Left',
+        RIGHT = 'Right',
+    }
+    enum Hybrid {
+        NUMERIC,
+        LEXICAL = 'Lexical',
+    }
+
+    it('encodes enums', () => {
+        // Bad.
+        expect(getEnumCodec(Feedback).encode(Feedback.BAD)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Feedback).encode('BAD')).toStrictEqual(b('00'));
+        expect(getEnumCodec(Feedback).encode(0)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Feedback).read(b('00'), 0)).toStrictEqual([Feedback.BAD, 1]);
+        expect(getEnumCodec(Feedback).read(b('ffff00'), 2)).toStrictEqual([Feedback.BAD, 3]);
+
+        // Good.
+        expect(getEnumCodec(Feedback).encode(Feedback.GOOD)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Feedback).encode('GOOD')).toStrictEqual(b('01'));
+        expect(getEnumCodec(Feedback).encode(1)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Feedback).read(b('01'), 0)).toStrictEqual([Feedback.GOOD, 1]);
+        expect(getEnumCodec(Feedback).read(b('ffff01'), 2)).toStrictEqual([Feedback.GOOD, 3]);
+
+        // Custom size.
+        const u64Feedback = getEnumCodec(Feedback, { size: u64() });
+        expect(u64Feedback.encode(Feedback.GOOD)).toStrictEqual(b('0100000000000000'));
+        expect(u64Feedback.read(b('0100000000000000'), 0)).toStrictEqual([Feedback.GOOD, 8]);
+
+        // Invalid examples.
+        // @ts-expect-error Invalid enum variant.
+        expect(() => getEnumCodec(Feedback).encode('Missing')).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__INVALID_ENUM_VARIANT, {
+                maxRange: 1,
+                minRange: 0,
+                value: 'Missing',
+                variants: ['BAD', 'GOOD'],
+            }),
+        );
+        expect(() => getEnumCodec(Feedback).read(new Uint8Array([2]), 0)).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__ENUM_DISCRIMINATOR_OUT_OF_RANGE, {
+                discriminator: 2,
+                maxRange: 1,
+                minRange: 0,
+            }),
+        );
+    });
+
+    it('encodes lexical enums', () => {
+        // Up.
+        expect(getEnumCodec(Direction).encode(Direction.UP)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Direction).encode('UP')).toStrictEqual(b('00'));
+        expect(getEnumCodec(Direction).encode('Up' as Direction)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Direction).read(b('00'), 0)).toStrictEqual([Direction.UP, 1]);
+        expect(getEnumCodec(Direction).read(b('ffff00'), 2)).toStrictEqual([Direction.UP, 3]);
+
+        // Down.
+        expect(getEnumCodec(Direction).encode(Direction.DOWN)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Direction).encode('DOWN')).toStrictEqual(b('01'));
+        expect(getEnumCodec(Direction).encode('Down' as Direction)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Direction).read(b('01'), 0)).toStrictEqual([Direction.DOWN, 1]);
+        expect(getEnumCodec(Direction).read(b('ffff01'), 2)).toStrictEqual([Direction.DOWN, 3]);
+
+        // Left.
+        expect(getEnumCodec(Direction).encode(Direction.LEFT)).toStrictEqual(b('02'));
+        expect(getEnumCodec(Direction).encode('LEFT')).toStrictEqual(b('02'));
+        expect(getEnumCodec(Direction).encode('Left' as Direction)).toStrictEqual(b('02'));
+        expect(getEnumCodec(Direction).read(b('02'), 0)).toStrictEqual([Direction.LEFT, 1]);
+        expect(getEnumCodec(Direction).read(b('ffff02'), 2)).toStrictEqual([Direction.LEFT, 3]);
+
+        // Right.
+        expect(getEnumCodec(Direction).encode(Direction.RIGHT)).toStrictEqual(b('03'));
+        expect(getEnumCodec(Direction).encode('RIGHT')).toStrictEqual(b('03'));
+        expect(getEnumCodec(Direction).encode('Right' as Direction)).toStrictEqual(b('03'));
+        expect(getEnumCodec(Direction).read(b('03'), 0)).toStrictEqual([Direction.RIGHT, 1]);
+        expect(getEnumCodec(Direction).read(b('ffff03'), 2)).toStrictEqual([Direction.RIGHT, 3]);
+
+        // Invalid examples.
+        // @ts-expect-error Invalid enum variant.
+        expect(() => getEnumCodec(Direction).encode('Diagonal')).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__INVALID_ENUM_VARIANT, {
+                maxRange: 3,
+                minRange: 0,
+                value: 'Diagonal',
+                variants: ['UP', 'DOWN', 'LEFT', 'RIGHT', 'Up', 'Down', 'Left', 'Right'],
+            }),
+        );
+        expect(() => getEnumCodec(Direction).read(new Uint8Array([4]), 0)).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__ENUM_DISCRIMINATOR_OUT_OF_RANGE, {
+                discriminator: 4,
+                maxRange: 3,
+                minRange: 0,
+            }),
+        );
+    });
+
+    it('encodes hybrid enums', () => {
+        // Numeric.
+        expect(getEnumCodec(Hybrid).encode(Hybrid.NUMERIC)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Hybrid).encode('NUMERIC')).toStrictEqual(b('00'));
+        expect(getEnumCodec(Hybrid).encode(0)).toStrictEqual(b('00'));
+        expect(getEnumCodec(Hybrid).read(b('00'), 0)).toStrictEqual([Hybrid.NUMERIC, 1]);
+        expect(getEnumCodec(Hybrid).read(b('ffff00'), 2)).toStrictEqual([Hybrid.NUMERIC, 3]);
+
+        // Lexical.
+        expect(getEnumCodec(Hybrid).encode(Hybrid.LEXICAL)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Hybrid).encode('LEXICAL')).toStrictEqual(b('01'));
+        expect(getEnumCodec(Hybrid).encode('Lexical' as Hybrid)).toStrictEqual(b('01'));
+        expect(getEnumCodec(Hybrid).read(b('01'), 0)).toStrictEqual([Hybrid.LEXICAL, 1]);
+        expect(getEnumCodec(Hybrid).read(b('ffff01'), 2)).toStrictEqual([Hybrid.LEXICAL, 3]);
+
+        // Invalid examples.
+        // @ts-expect-error Invalid enum variant.
+        expect(() => getEnumCodec(Hybrid).encode('Missing')).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__INVALID_ENUM_VARIANT, {
+                maxRange: 1,
+                minRange: 0,
+                value: 'Missing',
+                variants: ['NUMERIC', 'LEXICAL', 'Lexical'],
+            }),
+        );
+        expect(() => getEnumCodec(Hybrid).read(new Uint8Array([2]), 0)).toThrow(
+            new SolanaError(SOLANA_ERROR__CODECS__ENUM_DISCRIMINATOR_OUT_OF_RANGE, {
+                discriminator: 2,
+                maxRange: 1,
+                minRange: 0,
+            }),
+        );
+    });
+
+    it('has the right sizes', () => {
+        expect(getEnumCodec(Empty).fixedSize).toBe(1);
+        expect(getEnumCodec(Feedback).fixedSize).toBe(1);
+        expect(getEnumCodec(Direction).fixedSize).toBe(1);
+        expect(getEnumCodec(Hybrid).fixedSize).toBe(1);
+        expect(getEnumCodec(Feedback, { size: u32() }).fixedSize).toBe(4);
+    });
+});