From 55e3c9109ec27d26228957472ebfe8f45b0ab262 Mon Sep 17 00:00:00 2001
From: segfault-magnet <ahmed.sagdati.ets@gmail.com>
Date: Mon, 11 Nov 2024 03:09:24 +0100
Subject: [PATCH] decode fixed

---
 .../src/asm_instructions/contract_call.rs     | 31 +++++--------------
 .../src/asm_instructions/cursor.rs            | 10 ++++++
 packages/fuels-programs/src/debug.rs          |  5 +--
 wasm-tests/src/lib.rs                         |  1 +
 4 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/packages/fuels-programs/src/asm_instructions/contract_call.rs b/packages/fuels-programs/src/asm_instructions/contract_call.rs
index 2646b2689..361d37b9b 100644
--- a/packages/fuels-programs/src/asm_instructions/contract_call.rs
+++ b/packages/fuels-programs/src/asm_instructions/contract_call.rs
@@ -218,23 +218,11 @@ impl ContractCallData {
     pub fn decode(data: &[u8], gas_fwd: bool) -> Result<Self> {
         let mut data = WasmFriendlyCursor::new(data);
 
-        let amount = u64::from_be_bytes(
-            data.consume(8, "amount")?
-                .try_into()
-                .expect("will have exactly 8 bytes"),
-        );
-
-        let asset_id = AssetId::new(
-            data.consume(32, "asset id")?
-                .try_into()
-                .expect("will have exactly 32 bytes"),
-        );
-
-        let contract_id = ContractId::new(
-            data.consume(32, "contract id")?
-                .try_into()
-                .expect("will have exactly 32 bytes"),
-        );
+        let amount = u64::from_be_bytes(data.consume_fixed("amount")?);
+
+        let asset_id = AssetId::new(data.consume_fixed("asset id")?);
+
+        let contract_id = ContractId::new(data.consume_fixed("contract id")?);
 
         let _ = data.consume(8, "function selector offset")?;
 
@@ -242,8 +230,8 @@ impl ContractCallData {
 
         let fn_selector = {
             let fn_selector_len = {
-                let bytes = data.consume(8, "function selector lenght")?;
-                u64::from_be_bytes(bytes.try_into().expect("will have exactly 8 bytes")) as usize
+                let bytes = data.consume_fixed("function selector lenght")?;
+                u64::from_be_bytes(bytes) as usize
             };
             data.consume(fn_selector_len, "function selector")?.to_vec()
         };
@@ -253,10 +241,7 @@ impl ContractCallData {
                 .consume(data.unconsumed().saturating_sub(WORD_SIZE), "encoded_args")?
                 .to_vec();
 
-            let gas_fwd = {
-                let gas_fwd_bytes = data.consume(WORD_SIZE, "forwarded gas")?;
-                u64::from_be_bytes(gas_fwd_bytes.try_into().expect("exactly 8 bytes"))
-            };
+            let gas_fwd = { u64::from_be_bytes(data.consume_fixed("forwarded gas")?) };
 
             (encoded_args, Some(gas_fwd))
         } else {
diff --git a/packages/fuels-programs/src/asm_instructions/cursor.rs b/packages/fuels-programs/src/asm_instructions/cursor.rs
index 35005041b..a0077ebc3 100644
--- a/packages/fuels-programs/src/asm_instructions/cursor.rs
+++ b/packages/fuels-programs/src/asm_instructions/cursor.rs
@@ -24,6 +24,16 @@ impl<'a> WasmFriendlyCursor<'a> {
         }
     }
 
+    pub fn consume_fixed<const AMOUNT: usize>(
+        &mut self,
+        ctx: &'static str,
+    ) -> Result<[u8; AMOUNT]> {
+        Ok(self
+            .consume(AMOUNT, ctx)?
+            .try_into()
+            .expect("should have failed if not enough data"))
+    }
+
     pub fn consume_all(&self) -> &'a [u8] {
         self.data
     }
diff --git a/packages/fuels-programs/src/debug.rs b/packages/fuels-programs/src/debug.rs
index 02d84c4b1..fca122d6f 100644
--- a/packages/fuels-programs/src/debug.rs
+++ b/packages/fuels-programs/src/debug.rs
@@ -170,10 +170,7 @@ fn parse_loader_script(script: &[u8], data: &[u8]) -> Result<Option<(ScriptCallD
         return Ok(None);
     }
 
-    let blob_id = script_cursor
-        .consume(32, "blob id")?
-        .try_into()
-        .expect("will have exactly 32 bytes");
+    let blob_id = script_cursor.consume_fixed("blob id")?;
 
     let _data_section_len = script_cursor.consume(WORD_SIZE, "data section len")?;
 
diff --git a/wasm-tests/src/lib.rs b/wasm-tests/src/lib.rs
index d95d9d3c5..fca3e8d52 100644
--- a/wasm-tests/src/lib.rs
+++ b/wasm-tests/src/lib.rs
@@ -1,6 +1,7 @@
 extern crate alloc;
 
 // #[cfg(all(test, target_arch = "wasm32"))]
+#[cfg(test)]
 mod tests {
     use std::{default::Default, str::FromStr};