feat: port rule one-var (#833)

Author: fansenze

internal/config/config.go

@@ -230,6 +230,7 @@ import (
 	"github.com/web-infra-dev/rslint/internal/rules/no_var"
 	"github.com/web-infra-dev/rslint/internal/rules/no_with"
 	"github.com/web-infra-dev/rslint/internal/rules/object_shorthand"
+	"github.com/web-infra-dev/rslint/internal/rules/one_var"
 	"github.com/web-infra-dev/rslint/internal/rules/prefer_const"
 	core_prefer_promise_reject_errors "github.com/web-infra-dev/rslint/internal/rules/prefer_promise_reject_errors"
 	"github.com/web-infra-dev/rslint/internal/rules/prefer_rest_params"
@@ -729,6 +730,7 @@ func registerAllCoreEslintRules() {
 	GlobalRuleRegistry.Register("no-unreachable", no_unreachable.NoUnreachableRule)
 	GlobalRuleRegistry.Register("require-atomic-updates", require_atomic_updates.RequireAtomicUpdatesRule)
 	GlobalRuleRegistry.Register("object-shorthand", object_shorthand.ObjectShorthandRule)
+	GlobalRuleRegistry.Register("one-var", one_var.OneVarRule)
 	GlobalRuleRegistry.Register("no-dupe-else-if", no_dupe_else_if.NoDupeElseIfRule)
 	GlobalRuleRegistry.Register("no-throw-literal", no_throw_literal.NoThrowLiteralRule)
 	GlobalRuleRegistry.Register("no-useless-call", no_useless_call.NoUselessCallRule)

internal/rule/rule.go

@@ -99,6 +99,11 @@ func CreateRule(r Rule) Rule {
 type RuleMessage struct {
 	Id          string
 	Description string
+	// Data exposes the placeholder values that were substituted into
+	// Description (e.g. ESLint's `report({ data: { type } })`). Downstream
+	// reporters / IDE clients can use this for structured access. Optional —
+	// rules that don't carry placeholders may leave it nil.
+	Data map[string]string
 }
 
 type RuleFix struct {

internal/rules/no_loop_func/no_loop_func.go

@@ -316,34 +316,12 @@ func isSymbolDeclaredInside(sym *ast.Symbol, funcNode *ast.Node) bool {
 	return false
 }
 
-// GetVarDeclListKind returns the kind of a VariableDeclarationList: one of
-// "const", "let", "var", "using", "await using", or "" for anything else.
-//
-// IMPORTANT: tsgo encodes `await using` as `NodeFlagsConst | NodeFlagsUsing`
-// (see the node-flags definitions in typescript-go's ast package), so the aggregate flag
-// `NodeFlagsAwaitUsing` is NOT a single bit. We must inspect the individual
-// `NodeFlagsUsing` and `NodeFlagsConst` bits and only report `"await using"`
-// when BOTH are set, otherwise `flags & NodeFlagsAwaitUsing != 0` would
-// collapse plain `const` and plain `using` into `"await using"`.
+// GetVarDeclListKind is a thin wrapper around utils.GetVarDeclListKind kept
+// for backwards compatibility with the typescript-eslint counterpart in
+// internal/plugins/typescript/rules/no_loop_func, which imports this symbol.
+// New callers should use utils.GetVarDeclListKind directly.
 func GetVarDeclListKind(declList *ast.Node) string {
-	if declList == nil || declList.Kind != ast.KindVariableDeclarationList {
-		return ""
-	}
-	flags := declList.Flags
-	hasUsing := flags&ast.NodeFlagsUsing != 0
-	hasConst := flags&ast.NodeFlagsConst != 0
-	switch {
-	case hasUsing && hasConst:
-		return "await using"
-	case hasUsing:
-		return "using"
-	case hasConst:
-		return "const"
-	case flags&ast.NodeFlagsLet != 0:
-		return "let"
-	default:
-		return "var"
-	}
+	return utils.GetVarDeclListKind(declList)
 }
 
 // enclosingVarDeclOfBindingElement walks up through nested BindingElement /

internal/rules/no_var/no_var.go

@@ -2,8 +2,6 @@ package no_var
 
 import (
 	"github.com/microsoft/typescript-go/shim/ast"
-	"github.com/microsoft/typescript-go/shim/core"
-	"github.com/microsoft/typescript-go/shim/scanner"
 
 	"github.com/web-infra-dev/rslint/internal/rule"
 	"github.com/web-infra-dev/rslint/internal/utils"
@@ -41,7 +39,7 @@ var NoVarRule = rule.Rule{
 				}
 
 				if ctx.TypeChecker != nil && canFix(node, &ctx) {
-					varRange := getVarKeywordRange(node, ctx.SourceFile)
+					varRange := utils.GetVarKeywordRange(node, ctx.SourceFile)
 					ctx.ReportNodeWithFixes(reportNode, msg,
 						rule.RuleFixReplaceRange(varRange, "let"))
 				} else {
@@ -59,12 +57,6 @@ func isInDeclareGlobal(node *ast.Node) bool {
 	}) != nil
 }
 
-// getVarKeywordRange returns the text range of the `var` keyword in a VariableDeclarationList.
-func getVarKeywordRange(node *ast.Node, sourceFile *ast.SourceFile) core.TextRange {
-	s := scanner.GetScannerForSourceFile(sourceFile, node.Pos())
-	return core.NewTextRange(s.TokenStart(), s.TokenEnd())
-}
-
 // ---------- canFix: determines if var→let is safe ----------
 
 // canFix checks all 10 ESLint conditions to determine if var→let is safe.