spl: add spl token approve checked wrapper (#2401)

* add spl token approve checked wrapper

* update changelog

CHANGELOG.md

@@ -17,6 +17,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - cli: Add `idl close` command to close a program's IDL account ([#2329](https://github.com/coral-xyz/anchor/pull/2329)).
 - cli: `idl init` now supports very large IDL files ([#2329](https://github.com/coral-xyz/anchor/pull/2329)).
 - spl: Add `transfer_checked` function ([#2353](https://github.com/coral-xyz/anchor/pull/2353)).
+- spl: Add `approve_checked` function ([#2401](https://github.com/coral-xyz/anchor/pull/2401)).
 - cli: Add `--skip-build` option to the verify command ([#2387](https://github.com/coral-xyz/anchor/pull/2387)).
 - client: Add support for multithreading to the rust client: use flag `--multithreaded` ([#2321](https://github.com/coral-xyz/anchor/pull/2321)).
 - client: Add `async_rpc` a method which returns a nonblocking solana rpc client ([2322](https://github.com/coral-xyz/anchor/pull/2322)).

spl/src/token.rs

@@ -130,6 +130,34 @@ pub fn approve<'info>(
     .map_err(Into::into)
 }
 
+pub fn approve_checked<'info>(
+    ctx: CpiContext<'_, '_, '_, 'info, ApproveChecked<'info>>,
+    amount: u64,
+    decimals: u8,
+) -> Result<()> {
+    let ix = spl_token::instruction::approve_checked(
+        &spl_token::ID,
+        ctx.accounts.to.key,
+        ctx.accounts.mint.key,
+        ctx.accounts.delegate.key,
+        ctx.accounts.authority.key,
+        &[],
+        amount,
+        decimals,
+    )?;
+    solana_program::program::invoke_signed(
+        &ix,
+        &[
+            ctx.accounts.to.clone(),
+            ctx.accounts.mint.clone(),
+            ctx.accounts.delegate.clone(),
+            ctx.accounts.authority.clone(),
+        ],
+        ctx.signer_seeds,
+    )
+    .map_err(Into::into)
+}
+
 pub fn revoke<'info>(ctx: CpiContext<'_, '_, '_, 'info, Revoke<'info>>) -> Result<()> {
     let ix = spl_token::instruction::revoke(
         &spl_token::ID,
@@ -355,6 +383,14 @@ pub struct Approve<'info> {
     pub authority: AccountInfo<'info>,
 }
 
+#[derive(Accounts)]
+pub struct ApproveChecked<'info> {
+    pub to: AccountInfo<'info>,
+    pub mint: AccountInfo<'info>,
+    pub delegate: AccountInfo<'info>,
+    pub authority: AccountInfo<'info>,
+}
+
 #[derive(Accounts)]
 pub struct Revoke<'info> {
     pub source: AccountInfo<'info>,