Move the logic to decide if skip the agg programs build to a separate function

Author: maximopalopoli

aggregation_mode/proof_aggregator/build.rs

@@ -2,26 +2,29 @@ use risc0_build::{DockerOptionsBuilder, GuestOptionsBuilder};
 use std::collections::HashMap;
 use std::path::PathBuf;
 
-// Reference: https://docs.succinct.xyz/docs/sp1/writing-programs/compiling#advanced-build-options-1
-fn main() {
-    // This allows us to skip the guest build in CI or local environments where it's not needed (reducing the build time)
-    // Note: To use this flag, the aggregation programs should be already compiled, otherwise the compilation will be done anyway.
+// This allows us to skip the guest build in CI or local environments where it's not needed (reducing the build time)
+// Note: To use this flag, the aggregation programs should be already compiled, otherwise the compilation will be done anyway.
+fn should_skip_build() -> bool {
     if std::env::var("SKIP_AGG_PROGRAMS_BUILD")
         .map(|v| v == "1")
         .unwrap_or(false)
     {
         let out_dir = std::env::var("OUT_DIR").unwrap();
         let methods_path = PathBuf::from(out_dir).join("methods.rs");
 
-        if methods_path.exists() {
-            println!("cargo:warning=SKIP_AGG_PROGRAMS_BUILD=1: methods.rs already exists, skipping aggregation programs build");
-            return;
-        } else {
-            println!(
-                "cargo:warning=SKIP_AGG_PROGRAMS_BUILD=1 set, but {path} does not exist, running full build",
-                path = methods_path.display()
-            );
-        }
+        methods_path.exists()
+    } else {
+        false
+    }
+}
+
+// Reference: https://docs.succinct.xyz/docs/sp1/writing-programs/compiling#advanced-build-options-1
+fn main() {
+    if should_skip_build() {
+        println!("cargo:warning=SKIP_AGG_PROGRAMS_BUILD=1: methods.rs already exists, skipping aggregation programs build");
+        return;
+    } else {
+        println!("cargo:warning=SKIP_AGG_PROGRAMS_BUILD=1 set, but path does not exist, running full build");
     }
 
     sp1_build::build_program_with_args("./aggregation_programs/sp1", {