add an "es2022" target (#2012)

CHANGELOG.md

@@ -2,6 +2,18 @@
 
 ## Unreleased
 
+* Allow `es2022` as a target environment ([#2012](https://github.com/evanw/esbuild/issues/2012))
+
+    TypeScript recently [added support for `es2022`](https://devblogs.microsoft.com/typescript/announcing-typescript-4-6/#target-es2022) as a compilation target so esbuild now supports this too. Support for this is preliminary as there is no published ES2022 specification yet (i.e. https://tc39.es/ecma262/2021/ exists but https://tc39.es/ecma262/2022/ is a 404 error). The meaning of esbuild's `es2022` target may change in the future when the specification is finalized. Right now I have made the `es2022` target enable support for the syntax-related [finished proposals](https://github.com/tc39/proposals/blob/main/finished-proposals.md) that are marked as `2022`:
+
+    * Class fields
+    * Class private members
+    * Class static blocks
+    * Ergonomic class private member checks
+    * Top-level await
+
+    I have also included the "arbitrary module namespace names" feature since I'm guessing it will end up in the ES2022 specification (this syntax feature was added to the specification without a proposal). TypeScript has [not added support for this yet](https://github.com/microsoft/TypeScript/issues/40594).
+
 * Match `define` to strings in index expressions ([#2050](https://github.com/evanw/esbuild/issues/2050))
 
     With this release, configuring `--define:foo.bar=baz` now matches and replaces both `foo.bar` and `foo['bar']` expressions in the original source code. This is necessary for people who have enabled TypeScript's [`noPropertyAccessFromIndexSignature` feature](https://www.typescriptlang.org/tsconfig#noPropertyAccessFromIndexSignature), which prevents you from using normal property access syntax on a type with an index signature such as in the following code:

internal/compat/js_table.go

@@ -98,6 +98,7 @@ func (features JSFeature) Has(feature JSFeature) bool {
 var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ArbitraryModuleNamespaceNames: {
 		Chrome:  {{start: v{90, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{87, 0, 0}}},
 		Node:    {{start: v{16, 0, 0}}},
 	},
@@ -164,6 +165,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassField: {
 		Chrome:  {{start: v{73, 0, 0}}},
 		Edge:    {{start: v{79, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{69, 0, 0}}},
 		IOS:     {{start: v{14, 0, 0}}},
 		Node:    {{start: v{12, 0, 0}}},
@@ -173,6 +175,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateAccessor: {
 		Chrome:  {{start: v{84, 0, 0}}},
 		Edge:    {{start: v{84, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{14, 6, 0}}},
@@ -182,6 +185,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateBrandCheck: {
 		Chrome:  {{start: v{91, 0, 0}}},
 		Edge:    {{start: v{91, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{16, 9, 0}}},
@@ -191,6 +195,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateField: {
 		Chrome:  {{start: v{84, 0, 0}}},
 		Edge:    {{start: v{84, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{14, 6, 0}}},
@@ -200,6 +205,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateMethod: {
 		Chrome:  {{start: v{84, 0, 0}}},
 		Edge:    {{start: v{84, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{14, 6, 0}}},
@@ -209,6 +215,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateStaticAccessor: {
 		Chrome:  {{start: v{84, 0, 0}}},
 		Edge:    {{start: v{84, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{14, 6, 0}}},
@@ -218,6 +225,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateStaticField: {
 		Chrome:  {{start: v{74, 0, 0}}},
 		Edge:    {{start: v{79, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{12, 0, 0}}},
@@ -227,6 +235,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	ClassPrivateStaticMethod: {
 		Chrome:  {{start: v{84, 0, 0}}},
 		Edge:    {{start: v{84, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{90, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{14, 6, 0}}},
@@ -235,11 +244,13 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	},
 	ClassStaticBlocks: {
 		Chrome: {{start: v{91, 0, 0}}},
+		ES:     {{start: v{2022, 0, 0}}},
 		Node:   {{start: v{16, 11, 0}}},
 	},
 	ClassStaticField: {
 		Chrome:  {{start: v{73, 0, 0}}},
 		Edge:    {{start: v{79, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{75, 0, 0}}},
 		IOS:     {{start: v{15, 0, 0}}},
 		Node:    {{start: v{12, 0, 0}}},
@@ -483,6 +494,7 @@ var jsTable = map[JSFeature]map[Engine][]versionRange{
 	TopLevelAwait: {
 		Chrome:  {{start: v{89, 0, 0}}},
 		Edge:    {{start: v{89, 0, 0}}},
+		ES:      {{start: v{2022, 0, 0}}},
 		Firefox: {{start: v{89, 0, 0}}},
 		Node:    {{start: v{14, 8, 0}}},
 		Safari:  {{start: v{15, 0, 0}}},

internal/resolver/tsconfig_json.go

@@ -139,6 +139,8 @@ func ParseTSConfigJSON(
 					constraints[compat.ES] = []int{2020}
 				case "es2021":
 					constraints[compat.ES] = []int{2021}
+				case "es2022":
+					constraints[compat.ES] = []int{2022}
 				case "esnext":
 					// Nothing to do in this case
 				default:

pkg/api/api.go

@@ -125,6 +125,7 @@ const (
 	ES2019
 	ES2020
 	ES2021
+	ES2022
 )
 
 type Loader uint8

pkg/api/api_impl.go

@@ -307,6 +307,8 @@ func validateFeatures(log logger.Log, target Target, engines []Engine) (config.T
 		constraints[compat.ES] = []int{2020}
 	case ES2021:
 		constraints[compat.ES] = []int{2021}
+	case ES2022:
+		constraints[compat.ES] = []int{2022}
 	case ESNext:
 		targetFromAPI = config.TargetWasConfiguredIncludingESNext
 	case DefaultTarget:

pkg/cli/cli_impl.go

@@ -855,6 +855,7 @@ func parseTargets(targets []string, arg string) (target api.Target, engines []ap
 		"es2019": api.ES2019,
 		"es2020": api.ES2020,
 		"es2021": api.ES2021,
+		"es2022": api.ES2022,
 	}
 
 	validEngines := map[string]api.EngineName{

scripts/compat-table.js

@@ -157,10 +157,19 @@ mergeVersions('NullishCoalescing', { es2020: true })
 mergeVersions('OptionalChain', { es2020: true })
 mergeVersions('TypeofExoticObjectIsObject', { es2020: true }) // https://github.com/tc39/ecma262/pull/1441
 mergeVersions('LogicalAssignment', { es2021: true })
-mergeVersions('TopLevelAwait', {})
-mergeVersions('ArbitraryModuleNamespaceNames', {})
+mergeVersions('ClassField', { es2022: true })
+mergeVersions('ClassPrivateAccessor', { es2022: true })
+mergeVersions('ClassPrivateBrandCheck', { es2022: true })
+mergeVersions('ClassPrivateField', { es2022: true })
+mergeVersions('ClassPrivateMethod', { es2022: true })
+mergeVersions('ClassPrivateStaticAccessor', { es2022: true })
+mergeVersions('ClassPrivateStaticField', { es2022: true })
+mergeVersions('ClassPrivateStaticMethod', { es2022: true })
+mergeVersions('ClassStaticBlocks', { es2022: true })
+mergeVersions('ClassStaticField', { es2022: true })
+mergeVersions('TopLevelAwait', { es2022: true })
+mergeVersions('ArbitraryModuleNamespaceNames', { es2022: true })
 mergeVersions('ImportAssertions', {})
-mergeVersions('ClassStaticBlocks', {})
 
 // Manually copied from https://caniuse.com/?search=export%20*%20as
 mergeVersions('ExportStarAs', {