refactor: remove panic! from examples (#2454)

relates #2308

crates/oxc_codegen/examples/codegen.rs

@@ -9,10 +9,10 @@ use oxc_span::SourceType;
 // 1. create a `test.js`
 // 2. run `cargo run -p oxc_codegen --example codegen` or `just example codegen`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path)?;
     let source_type = SourceType::from_path(path).unwrap();
     let allocator = Allocator::default();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -22,7 +22,7 @@ fn main() {
             let error = error.with_source_code(source_text.clone());
             println!("{error:?}");
         }
-        return;
+        return Ok(());
     }
 
     println!("Original:");
@@ -37,4 +37,6 @@ fn main() {
     let minified = Codegen::<true>::new(source_text.len(), codegen_options).build(&ret.program);
     println!("Minified:");
     println!("{minified}");
+
+    Ok(())
 }

crates/oxc_linter/examples/linter.rs

@@ -17,10 +17,10 @@ use oxc_span::{SourceType, Span};
 // run `cargo run -p oxc_linter --example linter`
 // or `cargo watch -x "run -p oxc_linter --example linter"`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path)?;
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -28,7 +28,7 @@ fn main() {
     // Handle parser errors
     if !ret.errors.is_empty() {
         print_errors(&source_text, ret.errors);
-        return;
+        return Ok(());
     }
 
     let program = allocator.alloc(ret.program);
@@ -52,12 +52,13 @@ fn main() {
         }
     }
 
-    if !errors.is_empty() {
+    if errors.is_empty() {
+        println!("Success!");
+    } else {
         print_errors(&source_text, errors);
-        return;
     }
 
-    println!("Success!");
+    Ok(())
 }
 
 fn print_errors(source_text: &str, errors: Vec<oxc_diagnostics::Error>) {

crates/oxc_minifier/examples/minifier.rs

@@ -13,7 +13,7 @@ use pico_args::Arguments;
 // run `cargo run -p oxc_minifier --example minifier`
 // or `just watch "run -p oxc_minifier --example minifier"`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let mut args = Arguments::from_env();
 
     let name = args.subcommand().ok().flatten().unwrap_or_else(|| String::from("test.js"));
@@ -22,7 +22,7 @@ fn main() {
     let twice = args.contains("--twice");
 
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path)?;
     let source_type = SourceType::from_path(path).unwrap();
 
     let printed = minify(&source_text, source_type, mangle, whitespace);
@@ -32,6 +32,8 @@ fn main() {
         let printed = minify(&printed, source_type, mangle, whitespace);
         println!("{printed}");
     }
+
+    Ok(())
 }
 
 fn minify(source_text: &str, source_type: SourceType, mangle: bool, whitespace: bool) -> String {

crates/oxc_parser/examples/parser.rs

@@ -9,10 +9,10 @@ use oxc_span::SourceType;
 // run `cargo run -p oxc_parser --example parser`
 // or `cargo watch -x "run -p oxc_parser --example parser"`
 
-fn main() {
+fn main() -> Result<(), String> {
     let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path).map_err(|_| format!("Missing '{name}'"))?;
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -26,4 +26,6 @@ fn main() {
             println!("{error:?}");
         }
     }
+
+    Ok(())
 }

crates/oxc_parser/examples/visitor.rs

@@ -10,10 +10,10 @@ use oxc_span::SourceType;
 // run `cargo run -p oxc_parser --example visitor`
 // or `cargo watch -x "run -p oxc_parser --example visitor"`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path)?;
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -28,6 +28,8 @@ fn main() {
     let mut ast_pass = ASTPass::default();
     ast_pass.visit_program(&program);
     println!("{ast_pass:?}");
+
+    Ok(())
 }
 
 #[derive(Debug, Default)]

crates/oxc_prettier/examples/prettier.rs

@@ -12,14 +12,14 @@ use oxc_span::SourceType;
 // run `cargo run -p oxc_prettier --example prettier`
 // or `just example prettier`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let mut args = Arguments::from_env();
 
     let name = args.subcommand().ok().flatten().unwrap_or_else(|| String::from("test.js"));
     let semi = !args.contains("--no-semi");
 
     let path = Path::new(&name);
-    let source_text = std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found"));
+    let source_text = std::fs::read_to_string(path)?;
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).preserve_parens(false).parse();
@@ -31,4 +31,6 @@ fn main() {
     )
     .build(&ret.program);
     println!("{output}");
+
+    Ok(())
 }

crates/oxc_semantic/examples/cfg.rs

@@ -16,7 +16,7 @@ use petgraph::dot::{Config, Dot};
 //    - CFG blocks (test.cfg.txt)
 //    - CFG graph (test.dot)
 
-fn main() -> Result<(), std::io::Error> {
+fn main() -> std::io::Result<()> {
     let test_file_name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let ast_file_name = env::args().nth(1).unwrap_or_else(|| "test.ast.txt".to_string());
     let cfg_file_name = env::args().nth(1).unwrap_or_else(|| "test.cfg.txt".to_string());
@@ -27,10 +27,7 @@ fn main() -> Result<(), std::io::Error> {
     let cfg_file_path = Path::new(&cfg_file_name);
     let dot_file_path = Path::new(&dot_file_name);
 
-    let source_text = Arc::new(
-        std::fs::read_to_string(test_file_path)
-            .unwrap_or_else(|_| panic!("{test_file_name} not found")),
-    );
+    let source_text = Arc::new(std::fs::read_to_string(test_file_path)?);
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(test_file_path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -51,7 +48,8 @@ fn main() -> Result<(), std::io::Error> {
             .map(|error| error.with_source_code(Arc::clone(&source_text)).to_string())
             .join("\n\n");
 
-        panic!("Semantic analysis failed:\n\n{error_message}",);
+        println!("Semantic analysis failed:\n\n{error_message}",);
+        return Ok(());
     }
 
     let mut ast_nodes_by_block = HashMap::<_, Vec<_>>::new();

crates/oxc_semantic/examples/simple.rs

@@ -11,11 +11,10 @@ use oxc_span::SourceType;
 // run `cargo run -p oxc_semantic --example simple`
 // or `just watch "run -p oxc_semantic --example simple"`
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
     let path = Path::new(&name);
-    let source_text =
-        Arc::new(std::fs::read_to_string(path).unwrap_or_else(|_| panic!("{name} not found")));
+    let source_text = Arc::new(std::fs::read_to_string(path)?);
     let allocator = Allocator::default();
     let source_type = SourceType::from_path(path).unwrap();
     let ret = Parser::new(&allocator, &source_text, source_type).parse();
@@ -34,6 +33,8 @@ fn main() {
             .map(|error| error.with_source_code(Arc::clone(&source_text)).to_string())
             .join("\n\n");
 
-        panic!("Semantic analysis failed:\n\n{error_message}",);
+        println!("Semantic analysis failed:\n\n{error_message}",);
     }
+
+    Ok(())
 }