From 7af4c37df830bfd1e63c4bcbbef0896dd0d9320c Mon Sep 17 00:00:00 2001
From: Kei Sakamoto <thiry27015@gmail.com>
Date: Tue, 2 Dec 2025 18:21:36 +0900
Subject: [PATCH] feat: implement no-template-curly-in-string

---
 internal/config/config.go                     |  2 +
 .../no_template_curly_in_string.go            | 27 +++++++
 .../no_template_curly_in_string_test.go       | 74 +++++++++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 internal/rules/no_template_curly_in_string/no_template_curly_in_string.go
 create mode 100644 internal/rules/no_template_curly_in_string/no_template_curly_in_string_test.go

diff --git a/internal/config/config.go b/internal/config/config.go
index c43fab90..3c94eb88 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -95,6 +95,7 @@ import (
 	"github.com/web-infra-dev/rslint/internal/rules/no_constant_condition"
 	"github.com/web-infra-dev/rslint/internal/rules/no_constructor_return"
 	"github.com/web-infra-dev/rslint/internal/rules/no_debugger"
+	"github.com/web-infra-dev/rslint/internal/rules/no_template_curly_in_string"
 )
 
 // RslintConfig represents the top-level configuration array
@@ -459,6 +460,7 @@ func registerAllCoreEslintRules() {
 	GlobalRuleRegistry.Register("no-constant-condition", no_constant_condition.NoConstantConditionRule)
 	GlobalRuleRegistry.Register("no-constructor-return", no_constructor_return.NoConstructorReturnRule)
 	GlobalRuleRegistry.Register("no-debugger", no_debugger.NoDebuggerRule)
+	GlobalRuleRegistry.Register("no-template-curly-in-string", no_template_curly_in_string.NoTemplateCurlyInString)
 }
 
 // getAllTypeScriptEslintPluginRules returns all registered rules (for backward compatibility when no config is provided)
diff --git a/internal/rules/no_template_curly_in_string/no_template_curly_in_string.go b/internal/rules/no_template_curly_in_string/no_template_curly_in_string.go
new file mode 100644
index 00000000..7cca40e3
--- /dev/null
+++ b/internal/rules/no_template_curly_in_string/no_template_curly_in_string.go
@@ -0,0 +1,27 @@
+package no_template_curly_in_string
+
+import (
+	"regexp"
+
+	"github.com/microsoft/typescript-go/shim/ast"
+	"github.com/web-infra-dev/rslint/internal/rule"
+)
+
+// https://eslint.org/docs/latest/rules/no-template-curly-in-string
+var NoTemplateCurlyInString = rule.Rule{
+	Name: "no-template-curly-in-string",
+	Run: func(ctx rule.RuleContext, options any) rule.RuleListeners {
+		regex := regexp.MustCompile(`\$\{[^}]+\}`)
+		return rule.RuleListeners{
+			ast.KindStringLiteral: func(node *ast.Node) {
+				expr := node.AsStringLiteral()
+				if regex.MatchString(expr.Text) {
+					ctx.ReportNode(node, rule.RuleMessage{
+						Id:          "unexpectedTemplateExpression",
+						Description: "Template literal placeholder syntax in regular strings is not allowed.",
+					})
+				}
+			},
+		}
+	},
+}
diff --git a/internal/rules/no_template_curly_in_string/no_template_curly_in_string_test.go b/internal/rules/no_template_curly_in_string/no_template_curly_in_string_test.go
new file mode 100644
index 00000000..02855724
--- /dev/null
+++ b/internal/rules/no_template_curly_in_string/no_template_curly_in_string_test.go
@@ -0,0 +1,74 @@
+package no_template_curly_in_string
+
+import (
+	"testing"
+
+	"github.com/web-infra-dev/rslint/internal/plugins/typescript/rules/fixtures"
+	"github.com/web-infra-dev/rslint/internal/rule_tester"
+)
+
+func TestNoTemplateCurlyInString(t *testing.T) {
+	rule_tester.RunRuleTester(
+		fixtures.GetRootDir(),
+		"tsconfig.json",
+		t,
+		&NoTemplateCurlyInString,
+		// Valid cases - ported from ESLint
+		[]rule_tester.ValidTestCase{
+			{Code: "`Hello, ${name}`;"},
+			{Code: "templateFunction`Hello, ${name}`;"},
+			{Code: "`Hello, name`;"},
+			{Code: "'Hello, name';"},
+			{Code: "'Hello, ' + name;"},
+			{Code: "`Hello, ${index + 1}`"},
+			{Code: "`Hello, ${name + \" foo\"}`"},
+			{Code: "`Hello, ${name || \"foo\"}`"},
+			{Code: "`Hello, ${{foo: \"bar\"}.foo}`"},
+			{Code: "'$2'"},
+			{Code: "'${'"},
+			{Code: "'$}'"},
+			{Code: "'{foo}'"},
+			{Code: `'{foo: \"bar\"}'`},
+			{Code: "const number = 3"},
+		},
+		// Invalid cases - ported from ESLint
+		[]rule_tester.InvalidTestCase{
+			{
+				Code: "'Hello, ${name}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+			{
+				Code: "'${greeting}, ${name}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+			{
+				Code: "'Hello, ${index + 1}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+			{
+				Code: "'Hello, ${name + \\\" foo\\\"}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+			{
+				Code: "'Hello, ${name || \\\"foo\\\"}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+			{
+				Code: "'Hello, ${{foo: \\\"bar\\\"}.foo}'",
+				Errors: []rule_tester.InvalidTestCaseError{
+					{MessageId: "unexpectedTemplateExpression", Line: 1, Column: 1},
+				},
+			},
+		},
+	)
+}