From 8d2e2d53c20a5c39b698d0499f2df8b71e275ac7 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Thu, 25 Apr 2024 15:22:21 -0700
Subject: [PATCH] Move RegExp flag version mapping to
 LanguageFeatureMinimumTarget (#58311)

---
 src/compiler/scanner.ts | 33 ++++++++++++++++-----------------
 src/compiler/types.ts   |  5 +++++
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/compiler/scanner.ts b/src/compiler/scanner.ts
index f8a8c52debf..2d26d915aa2 100644
--- a/src/compiler/scanner.ts
+++ b/src/compiler/scanner.ts
@@ -19,6 +19,7 @@ import {
     JSDocSyntaxKind,
     JsxTokenSyntaxKind,
     KeywordSyntaxKind,
+    LanguageFeatureMinimumTarget,
     LanguageVariant,
     last,
     LineAndCharacter,
@@ -293,15 +294,12 @@ const charToRegExpFlag = new Map(Object.entries({
     y: RegularExpressionFlags.Sticky,
 }));
 
-const regExpFlagToFirstAvailableLanguageVersion = new Map([
-    [RegularExpressionFlags.HasIndices, ScriptTarget.ES2022],
-    [RegularExpressionFlags.Global, ScriptTarget.ES3],
-    [RegularExpressionFlags.IgnoreCase, ScriptTarget.ES3],
-    [RegularExpressionFlags.Multiline, ScriptTarget.ES3],
-    [RegularExpressionFlags.DotAll, ScriptTarget.ES2018],
-    [RegularExpressionFlags.Unicode, ScriptTarget.ES2015],
-    [RegularExpressionFlags.UnicodeSets, ScriptTarget.ESNext],
-    [RegularExpressionFlags.Sticky, ScriptTarget.ES2015],
+const regExpFlagToFirstAvailableLanguageVersion = new Map<RegularExpressionFlags, LanguageFeatureMinimumTarget>([
+    [RegularExpressionFlags.HasIndices, LanguageFeatureMinimumTarget.RegularExpressionFlagsHasIndices],
+    [RegularExpressionFlags.DotAll, LanguageFeatureMinimumTarget.RegularExpressionFlagsDotAll],
+    [RegularExpressionFlags.Unicode, LanguageFeatureMinimumTarget.RegularExpressionFlagsUnicode],
+    [RegularExpressionFlags.UnicodeSets, LanguageFeatureMinimumTarget.RegularExpressionFlagsUnicodeSets],
+    [RegularExpressionFlags.Sticky, LanguageFeatureMinimumTarget.RegularExpressionFlagsSticky],
 ]);
 
 /*
@@ -2461,10 +2459,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                     }
                     else {
                         regExpFlags |= flag;
-                        const availableFrom = regExpFlagToFirstAvailableLanguageVersion.get(flag)!;
-                        if (languageVersion < availableFrom) {
-                            error(Diagnostics.This_regular_expression_flag_is_only_available_when_targeting_0_or_later, p, 1, getNameOfScriptTarget(availableFrom));
-                        }
+                        checkRegularExpressionFlagAvailable(flag, p);
                     }
                 }
                 p++;
@@ -2742,10 +2737,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                     }
                     else {
                         currFlags |= flag;
-                        const availableFrom = regExpFlagToFirstAvailableLanguageVersion.get(flag)!;
-                        if (languageVersion < availableFrom) {
-                            error(Diagnostics.This_regular_expression_flag_is_only_available_when_targeting_0_or_later, pos, 1, getNameOfScriptTarget(availableFrom));
-                        }
+                        checkRegularExpressionFlagAvailable(flag, pos);
                     }
                     pos++;
                 }
@@ -3446,6 +3438,13 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                 }
             });
         }
+
+        function checkRegularExpressionFlagAvailable(flag: RegularExpressionFlags, pos: number) {
+            const availableFrom = regExpFlagToFirstAvailableLanguageVersion.get(flag) as ScriptTarget | undefined;
+            if (availableFrom && languageVersion < availableFrom) {
+                error(Diagnostics.This_regular_expression_flag_is_only_available_when_targeting_0_or_later, pos, 1, getNameOfScriptTarget(availableFrom));
+            }
+        }
     }
 
     function appendIfCommentDirective(
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 70397a75908..76f8193ae12 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -8231,6 +8231,8 @@ export const enum LanguageFeatureMinimumTarget {
     ArrowFunctions = ScriptTarget.ES2015,
     BlockScopedVariables = ScriptTarget.ES2015,
     ObjectAssign = ScriptTarget.ES2015,
+    RegularExpressionFlagsUnicode = ScriptTarget.ES2015,
+    RegularExpressionFlagsSticky = ScriptTarget.ES2015,
 
     // ES2016 Features
     Exponentiation = ScriptTarget.ES2016, // `x ** y`
@@ -8243,6 +8245,7 @@ export const enum LanguageFeatureMinimumTarget {
     AsyncGenerators = ScriptTarget.ES2018, // `async function * f() { }`
     AsyncIteration = ScriptTarget.ES2018, // `Symbol.asyncIterator`
     ObjectSpreadRest = ScriptTarget.ES2018, // `{ ...obj }`
+    RegularExpressionFlagsDotAll = ScriptTarget.ES2018,
 
     // ES2019 Features
     BindinglessCatch = ScriptTarget.ES2019, // `try { } catch { }`
@@ -8259,6 +8262,7 @@ export const enum LanguageFeatureMinimumTarget {
     TopLevelAwait = ScriptTarget.ES2022,
     ClassFields = ScriptTarget.ES2022,
     PrivateNamesAndClassStaticBlocks = ScriptTarget.ES2022, // `class C { static {} #x = y, #m() {} }`, `#x in y`
+    RegularExpressionFlagsHasIndices = ScriptTarget.ES2022,
 
     // ES2023 Features
     ShebangComments = ScriptTarget.ESNext,
@@ -8269,6 +8273,7 @@ export const enum LanguageFeatureMinimumTarget {
     //       transformers/esnext.ts, commandLineParser.ts, and the contents of each lib/esnext.*.d.ts file.
     UsingAndAwaitUsing = ScriptTarget.ESNext, // `using x = y`, `await using x = y`
     ClassAndClassElementDecorators = ScriptTarget.ESNext, // `@dec class C {}`, `class C { @dec m() {} }`
+    RegularExpressionFlagsUnicodeSets = ScriptTarget.ESNext,
 }
 
 // dprint-ignore