feat: starknet contract and cairo program

.gitignore

@@ -1 +1 @@
-target
+target/

README.md

@@ -16,7 +16,20 @@ This Cairo Bootcamp is designed to:
 ---
 
 ## 📁 Repository Structure
+The repository is organized into the following directories
 .
-├── cairo_programs/ # Pure Cairo programs (stateless logic)
+├── cairo_program/ # Pure Cairo programs (stateless logic)
+│   ├── README.md
+│   ├── Scarb.lock
+│   ├── Scarb.toml
+│   ├── src
+│   └── target
+├── README.md
 ├── starknet_contracts/ # Smart contracts (stateful logic)
-└── README.md
+│   ├── Scarb.lock
+│   ├── Scarb.toml
+│   ├── snfoundry.toml
+│   └── src
+└── target
+    ├── CACHEDIR.TAG
+    └── cairo-language-server

cairo_program/Scarb.lock

@@ -4,3 +4,21 @@ version = 1
 [[package]]
 name = "cairo_6"
 version = "0.1.0"
+dependencies = [
+ "snforge_std",
+]
+
+[[package]]
+name = "snforge_scarb_plugin"
+version = "0.59.0"
+source = "registry+https://scarbs.xyz/"
+checksum = "sha256:871fba677c03b66a1bf40815dac0ab1b385eb1b9be6e6c3cf2ad9788eeb2b6bb"
+
+[[package]]
+name = "snforge_std"
+version = "0.59.0"
+source = "registry+https://scarbs.xyz/"
+checksum = "sha256:3620924fa08bd2d740b2b5b01ef86c8dab3d4b9c2206387c8dbdc8d2ec15133e"
+dependencies = [
+ "snforge_scarb_plugin",
+]

cairo_program/Scarb.toml

@@ -3,14 +3,18 @@ name = "cairo_6"
 version = "0.1.0"
 edition = "2025_12"
 
-# See more keys and their definitions at https://docs.swmansion.com/scarb/docs/reference/manifest.html
+[lib]
 
-[executable]
+[dependencies]
 
-[cairo]
-enable-gas = false
+[dev-dependencies]
+snforge_std = "0.59.0"
+assert_macros = "2.18.0"
 
-[dependencies]
-cairo_execute = "2.18.0"
+[scripts]
+test = "snforge test"
+
+[tool.scarb]
+allow-prebuilt-plugins = ["snforge_std"]
 
 

cairo_program/src/integer.cairo

@@ -1,20 +1,62 @@
-#[executable]
-fn main() {
-    let result: u8 = add_num(5, 6);
-    println!("the sum of x & y is: {}", result);
-    assert(result == 11, 'invalid sum logic');
-
-    let sub_result: u8 = sub_num(10, 5);
-    println!("sub result is: {}", sub_result);
-    assert(sub_result == 5, 'invalid sub logic');
+// === Arithmetic Functions
+pub fn add_num(x: u32, y: u32) -> Result<u32, felt252> {
+    let result: u256 = x.into() + y.into();
+    result.try_into().ok_or('Addition overflow')
 }
 
-// addition logic
-fn add_num(x: u8, y: u8) -> u8 {
-    x + y
+pub fn sub_num(x: u32, y: u32) -> Result<u32, felt252> {
+    if x < y {
+        Result::Err('Subtraction underflow')
+    } else {
+        Result::Ok(x - y)
+    }
 }
 
-// subtraction logic
-fn sub_num(x: u8, y: u8) -> u8 {
-    return x - y;
+pub fn multiply_num(x: u32, y: u32) -> Result<u32, felt252> {
+    let result: u256 = x.into() * y.into();
+    result.try_into().ok_or('Multiplication overflow')
+}
+
+pub fn divide_num(x: u32, y: u32) -> Result<u32, felt252> {
+    if y == 0 {
+        Result::Err('Division by zero')
+    } else {
+        Result::Ok(x / y)
+    }
+}
+
+// === Tests
+#[cfg(test)]
+mod tests {
+    use super::{add_num, sub_num, multiply_num, divide_num};
+
+    #[test]
+    fn test_add_num() {
+        assert!(add_num(20, 7) == Result::Ok(27), "add failed");
+    }
+
+    #[test]
+    fn test_sub_num_ok() {
+        assert!(sub_num(16, 9) == Result::Ok(7), "sub failed");
+    }
+
+    #[test]
+    fn test_sub_num_underflow() {
+        assert!(sub_num(3, 10) == Result::Err('Subtraction underflow'), "underflow check failed");
+    }
+
+    #[test]
+    fn test_multiply_num() {
+        assert!(multiply_num(5, 6) == Result::Ok(30), "multiply failed");
+    }
+
+    #[test]
+    fn test_divide_num_ok() {
+        assert!(divide_num(20, 5) == Result::Ok(4), "divide failed");
+    }
+
+    #[test]
+    fn test_divide_by_zero() {
+        assert!(divide_num(10, 0) == Result::Err('Division by zero'), "div zero check failed");
+    }
 }

cairo_program/src/lib.cairo

@@ -1,5 +1,5 @@
 // mod hello_world;
 // mod short_string;
-// mod integer;
+pub mod integer;
 // mod bool;
-mod bytearray;
+// mod bytearray;

cairo_runner/Scarb.lock

@@ -0,0 +1,13 @@
+# Code generated by scarb DO NOT EDIT.
+version = 1
+
+[[package]]
+name = "cairo_6"
+version = "0.1.0"
+
+[[package]]
+name = "cairo_runner"
+version = "0.1.0"
+dependencies = [
+ "cairo_6",
+]

cairo_runner/Scarb.toml

@@ -0,0 +1,13 @@
+[package]
+name = "cairo_runner"
+version = "0.1.0"
+edition = "2025_12"
+
+[executable]
+
+[cairo]
+enable-gas = false
+
+[dependencies]
+cairo_execute = "2.18.0"
+cairo_6 = { path = "../cairo_program" }

cairo_runner/src/lib.cairo

@@ -0,0 +1,54 @@
+use cairo_6::integer::{add_num, sub_num, multiply_num, divide_num};
+
+#[executable]
+fn main() {
+    // === Addition
+    let a: u32 = 20;
+    let b: u32 = 7;
+    match add_num(a, b) {
+        Result::Ok(val) => println!("Adding {} + {} = {}.", a, b, val),
+        Result::Err(err) => println!("Adding {} + {} failed: {}.", a, b, err),
+    }
+
+    // === Subtraction
+    let (c, d) = (16_u32, 9_u32);
+    match sub_num(c, d) {
+        Result::Ok(val) => println!("Subtracting {} - {} = {}.", c, d, val),
+        Result::Err(err) => println!("Subtracting {} - {} failed: {}.", c, d, err),
+    }
+
+    // Underflow case
+    let (e, f) = (3_u32, 10_u32);
+    match sub_num(e, f) {
+        Result::Ok(val) => println!("Subtracting {} - {} = {}.", e, f, val),
+        Result::Err(err) => println!("Subtracting {} - {} failed: {}.", e, f, err),
+    }
+
+    // === Multiplication
+    let (g, h) = (5_u32, 6_u32);
+    match multiply_num(g, h) {
+        Result::Ok(val) => println!("Multiplying {} * {} = {}.", g, h, val),
+        Result::Err(err) => println!("Multiplying {} * {} failed: {}.", g, h, err),
+    }
+
+    // Overflow case
+    let (i, j) = (4294967295_u32, 2_u32);
+    match multiply_num(i, j) {
+        Result::Ok(val) => println!("Multiplying {} * {} = {}.", i, j, val),
+        Result::Err(err) => println!("Multiplying {} * {} failed: {}.", i, j, err),
+    }
+
+    // === Division
+    let (k, l) = (20_u32, 5_u32);
+    match divide_num(k, l) {
+        Result::Ok(val) => println!("{} / {} = {}", k, l, val),
+        Result::Err(err) => println!("{} / {} failed: {}", k, l, err),
+    }
+
+    // By zero
+    let (m, n) = (10_u32, 0_u32);
+    match divide_num(m, n) {
+        Result::Ok(val) => println!("Dividing {} / {} = {}.", m, n, val),
+        Result::Err(err) => println!("Dividing {} / {} failed: {}.", m, n, err),
+    }
+}

starknet_contracts/Scarb.lock

@@ -1,17 +1,21 @@
 # Code generated by scarb DO NOT EDIT.
 version = 1
 
+[[package]]
+name = "cairo_6"
+version = "0.1.0"
+
 [[package]]
 name = "snforge_scarb_plugin"
-version = "0.56.0"
+version = "0.59.0"
 source = "registry+https://scarbs.xyz/"
-checksum = "sha256:d5f2d878f7ae36c8149c517e2d618a95d7833598a76083cb12ea3f00da06a618"
+checksum = "sha256:871fba677c03b66a1bf40815dac0ab1b385eb1b9be6e6c3cf2ad9788eeb2b6bb"
 
 [[package]]
 name = "snforge_std"
-version = "0.56.0"
+version = "0.59.0"
 source = "registry+https://scarbs.xyz/"
-checksum = "sha256:87dfe06ffd5cf1d5a075b7a5c8dff442b66d0eeaf27921140cf446213eb29a68"
+checksum = "sha256:3620924fa08bd2d740b2b5b01ef86c8dab3d4b9c2206387c8dbdc8d2ec15133e"
 dependencies = [
  "snforge_scarb_plugin",
 ]
@@ -20,5 +24,6 @@ dependencies = [
 name = "starknet_contracts"
 version = "0.1.0"
 dependencies = [
+ "cairo_6",
  "snforge_std",
 ]

starknet_contracts/Scarb.toml

@@ -7,14 +7,17 @@ edition = "2024_07"
 
 [dependencies]
 starknet = "2.18.0"
+cairo_6 = { path = "../cairo_program" }
 
 [dev-dependencies]
-snforge_std = "0.56.0"
+snforge_std = "0.59.0"
 assert_macros = "2.18.0"
 
 [[target.starknet-contract]]
 sierra = true
 
+[lib]
+
 [scripts]
 test = "snforge test"
 

starknet_contracts/snfoundry.toml

@@ -1,3 +1,5 @@
+[sncast.default]
+account = "cairo_account"
 # Visit https://foundry-rs.github.io/starknet-foundry/appendix/snfoundry-toml.html
 # and https://foundry-rs.github.io/starknet-foundry/projects/configuration.html for more information