Don't start server if compilation fails

start-debug-mode.sh

 
 wasm-pack build --target web --dev --out-dir www/pkg -- --features "with-measure"
 
-basic-http-server ./www -a 0.0.0.0:4001
+if [ $? -eq 0 ]; then
+  basic-http-server ./www -a 0.0.0.0:4001
+fi

start-profiling.sh

 
 wasm-pack build --target web --profiling --out-dir www/pkg
 
-basic-http-server ./www -a 0.0.0.0:4001
+if [ $? -eq 0 ]; then
+  basic-http-server ./www -a 0.0.0.0:4001
+fi

start-release-mode.sh

 
 wasm-pack build --target web --release --out-dir www/pkg
 
-basic-http-server ./www -a 0.0.0.0:4001
+if [ $? -eq 0 ]; then
+  basic-http-server ./www -a 0.0.0.0:4001
+fi