# @typescript-eslint/no-unnecessary-template-expression

> Disallow `${}` in a template literal where plain text or the value itself does the same

A template literal that holds nothing but one string, like `` `${name}` ``, is that string. A literal inside `${}`, like `` `${"px"}` ``, can be written as plain text. In both cases the `${}` makes the reader look for a conversion that doesn't happen.

The rule reports a template that's only one `${}` with a string in it, and any `${}` that holds a string, number, bigint, boolean, regular expression or template literal, `null`, `undefined`, `NaN` or `Infinity`. Template literal types are checked too. Tagged templates aren't.

`--fix` removes the `${}`.

{/* Generated by src/codegen/lint-rule-docs.ts. Do not edit this section. */}

## Configure

Off by default. This rule needs types, so turning it on makes `bun lint` type check your code first.

```toml bunfig.toml
[lint.rules]
"@typescript-eslint/no-unnecessary-template-expression" = "error" # or "warn"
```

{/* End of the generated section. */}

## Examples

Reported:

{/* bad {"count": 4} */}
```ts
function describe(name: string, width: number) {
  const title = `${name}`;
  const size = `${width}${"px"}`;
  const retries = `retries: ${3}`;
  return [title, size, retries];
}

type Size = `${number}${"px"}`;
```

Not reported:

{/* good */}
```ts
function describe(name: string, width: number) {
  const title = name;
  const size = `${width}px`;
  const retries = "retries: 3";
  return [title, size, retries];
}

type Size = `${number}px`;
```

A template that turns another type into a string does real work:

{/* good */}
```ts
function toText(count: number) {
  return `${count}`;
}
```

Spaces at the end of a line are easy to miss and editors often strip them, so `${" "}` before a line break is allowed:

{/* good */}
```ts
const usage = `Usage:${" "}
  save <file>`;
```