feat(linter): no_template_curly_in_string (#2763)

Rule detail:
https://eslint.org/docs/latest/rules/no-template-curly-in-string

At first I implemented it with regex, but I think you are trying to
avoid it for performance reasons, so I did it by searching for the
chars.

I had some problems showing the span in the case of 'Hello, ${{foo:
"bar"}.foo}' I think it turned out more or less well, however, if you
think it can be done in another way I am willing to do it .

---------

Co-authored-by: j.buendia <j.buendia>

crates/oxc_linter/src/rules.rs

@@ -96,6 +96,7 @@ mod eslint {
     pub mod no_setter_return;
     pub mod no_shadow_restricted_names;
     pub mod no_sparse_arrays;
+    pub mod no_template_curly_in_string;
     pub mod no_ternary;
     pub mod no_this_before_super;
     pub mod no_undef;
@@ -369,6 +370,7 @@ oxc_macros::declare_all_lint_rules! {
     eslint::max_params,
     eslint::no_ternary,
     eslint::no_this_before_super,
+    eslint::no_template_curly_in_string,
     eslint::no_array_constructor,
     eslint::no_async_promise_executor,
     eslint::no_bitwise,

crates/oxc_linter/src/rules/eslint/no_template_curly_in_string.rs

@@ -0,0 +1,110 @@
+use oxc_ast::AstKind;
+use oxc_diagnostics::{
+    miette::{self, Diagnostic},
+    thiserror::Error,
+};
+use oxc_macros::declare_oxc_lint;
+use oxc_span::Span;
+
+use crate::{context::LintContext, rule::Rule, AstNode};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint(no-template-curly-in-string): Unexpected template string expression")]
+#[diagnostic(
+    severity(warning),
+    help("Disallow template literal placeholder syntax in regular strings")
+)]
+struct NoTemplateCurlyInStringDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct NoTemplateCurlyInString;
+
+declare_oxc_lint!(
+    /// ### What it does
+    /// Disallow template literal placeholder syntax in regular strings
+    ///
+    /// ### Why is this bad?
+    /// ECMAScript 6 allows programmers to create strings containing variable or expressions using template literals, instead of string concatenation, by writing expressions like ${variable} between two backtick quotes (`). It can be easy to use the wrong quotes when wanting to use template literals, by writing "${variable}", and end up with the literal value "${variable}" instead of a string containing the value of the injected expressions.
+    ///
+    /// ### Example
+    /// ```javascript
+    /// /*eslint no-template-curly-in-string: "error"*/
+    /// "Hello ${name}!";
+    /// 'Hello ${name}!';
+    /// "Time: ${12 * 60 * 60 * 1000}";
+    /// ```
+    NoTemplateCurlyInString,
+    style
+);
+
+impl Rule for NoTemplateCurlyInString {
+    fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+        if let AstKind::StringLiteral(literal) = node.kind() {
+            let text = literal.value.as_str();
+            if let Some(start_index) = text.find("${") {
+                let mut open_braces_count = 0;
+                let mut end_index = None;
+
+                for (i, c) in text[start_index..].char_indices() {
+                    let real_index = start_index + i;
+                    if c == '{' {
+                        open_braces_count += 1;
+                    } else if c == '}' && open_braces_count > 0 {
+                        open_braces_count -= 1;
+                        if open_braces_count == 0 {
+                            end_index = Some(real_index);
+                            break;
+                        }
+                    }
+                }
+
+                if let Some(end_index) = end_index {
+                    let literal_span_start = literal.span.start + 1;
+                    let match_start = u32::try_from(start_index)
+                        .expect("Conversion from usize to u32 failed for match_start");
+                    let match_end = u32::try_from(end_index + 1)
+                        .expect("Conversion from usize to u32 failed for match_end");
+                    ctx.diagnostic(NoTemplateCurlyInStringDiagnostic(Span::new(
+                        literal_span_start + match_start,
+                        literal_span_start + match_end,
+                    )));
+                }
+            }
+        }
+    }
+}
+
+#[test]
+fn test() {
+    use crate::tester::Tester;
+
+    let pass = vec![
+        "`Hello, ${name}`;",
+        "templateFunction`Hello, ${name}`;",
+        "`Hello, name`;",
+        "'Hello, name';",
+        "'Hello, ' + name;",
+        "`Hello, ${index + 1}`",
+        r#"`Hello, ${name + " foo"}`"#,
+        r#"`Hello, ${name || "foo"}`"#,
+        r#"`Hello, ${{foo: "bar"}.foo}`"#,
+        "'$2'",
+        "'${'",
+        "'$}'",
+        "'{foo}'",
+        r#"'{foo: "bar"}'"#,
+        "const number = 3",
+    ];
+
+    let fail = vec![
+        "'Hello, ${name}'",
+        r#""Hello, ${name}""#,
+        "'${greeting}, ${name}'",
+        "'Hello, ${index + 1}'",
+        r#"'Hello, ${name + " foo"}'"#,
+        r#"'Hello, ${name || "foo"}'"#,
+        r#"'Hello, ${{foo: "bar"}.foo}'"#,
+    ];
+
+    Tester::new(NoTemplateCurlyInString::NAME, pass, fail).test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/no_template_curly_in_string.snap

@@ -0,0 +1,52 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: no_template_curly_in_string
+---
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ 'Hello, ${name}'
+   ·         ───────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ "Hello, ${name}"
+   ·         ───────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:2]
+ 1 │ '${greeting}, ${name}'
+   ·  ───────────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ 'Hello, ${index + 1}'
+   ·         ────────────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ 'Hello, ${name + " foo"}'
+   ·         ────────────────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ 'Hello, ${name || "foo"}'
+   ·         ────────────────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings
+
+  ⚠ eslint(no-template-curly-in-string): Unexpected template string expression
+   ╭─[no_template_curly_in_string.tsx:1:9]
+ 1 │ 'Hello, ${{foo: "bar"}.foo}'
+   ·         ───────────────────
+   ╰────
+  help: Disallow template literal placeholder syntax in regular strings