fix(es/minifier): Fix minifier (#1985)

swc_ecma_minifier:
 - Don't create an identifier starting with number. (#1983)
 - Fix panic. (#1984)
 - Don't use time api on wasm. (#1982)

Cargo.lock

@@ -2502,7 +2502,7 @@ dependencies = [
 
 [[package]]
 name = "swc_ecma_minifier"
-version = "0.16.0"
+version = "0.16.1"
 dependencies = [
  "ansi_term 0.12.1",
  "anyhow",
@@ -3197,7 +3197,7 @@ checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
 
 [[package]]
 name = "wasm"
-version = "1.2.69"
+version = "1.2.70"
 dependencies = [
  "console_error_panic_hook",
  "once_cell",

ecmascript/minifier/Cargo.toml

@@ -7,7 +7,7 @@ include = ["Cargo.toml", "src/**/*.rs", "src/lists/*.json"]
 license = "Apache-2.0/MIT"
 name = "swc_ecma_minifier"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.16.0"
+version = "0.16.1"
 
 [features]
 debug = []

ecmascript/minifier/src/analyzer/mod.rs

@@ -1,6 +1,7 @@
 use self::ctx::Ctx;
 use crate::util::can_end_conditionally;
 use crate::util::idents_used_by;
+use crate::util::now;
 use fxhash::FxHashMap;
 use fxhash::FxHashSet;
 use std::collections::hash_map::Entry;
@@ -25,7 +26,7 @@ pub(crate) fn analyze<N>(n: &N) -> ProgramData
 where
     N: VisitWith<UsageAnalyzer>,
 {
-    let start_time = Instant::now();
+    let start_time = now();
 
     let mut v = UsageAnalyzer {
         data: Default::default(),
@@ -36,9 +37,11 @@ where
     let top_scope = v.scope;
     v.data.top.merge(top_scope, false);
 
-    let end_time = Instant::now();
+    if let Some(start_time) = start_time {
+        let end_time = Instant::now();
 
-    log::debug!("Scope analysis took {:?}", end_time - start_time);
+        log::debug!("Scope analysis took {:?}", end_time - start_time);
+    }
 
     v.data
 }

ecmascript/minifier/src/compress/mod.rs

@@ -8,6 +8,7 @@ use crate::debug::dump;
 use crate::debug::invoke;
 use crate::marks::Marks;
 use crate::option::CompressOptions;
+use crate::util::now;
 use crate::util::Optional;
 #[cfg(feature = "pretty_assertions")]
 use pretty_assertions::assert_eq;
@@ -157,7 +158,7 @@ impl VisitMut for Compressor<'_> {
                 self.pass
             );
 
-            let start_time = Instant::now();
+            let start_time = now();
 
             let mut visitor = expr_simplifier();
             n.visit_mut_with(&mut visitor);
@@ -169,13 +170,15 @@ impl VisitMut for Compressor<'_> {
                 }
             }
 
-            let end_time = Instant::now();
+            if let Some(start_time) = start_time {
+                let end_time = Instant::now();
 
-            log::info!(
-                "compress: expr_simplifier took {:?} (pass = {})",
-                end_time - start_time,
-                self.pass
-            );
+                log::info!(
+                    "compress: expr_simplifier took {:?} (pass = {})",
+                    end_time - start_time,
+                    self.pass
+                );
+            }
 
             if cfg!(feature = "debug") && !visitor.changed() {
                 let simplified = dump(&n.clone().fold_with(&mut fixer(None)));
@@ -193,7 +196,7 @@ impl VisitMut for Compressor<'_> {
         {
             log::info!("compress: Running optimizer (pass = {})", self.pass);
 
-            let start_time = Instant::now();
+            let start_time = now();
             // TODO: reset_opt_flags
             //
             // This is swc version of `node.optimize(this);`.
@@ -207,13 +210,15 @@ impl VisitMut for Compressor<'_> {
             n.visit_mut_with(&mut visitor);
             self.changed |= visitor.changed();
 
-            let end_time = Instant::now();
+            if let Some(start_time) = start_time {
+                let end_time = Instant::now();
 
-            log::info!(
-                "compress: Optimizer took {:?} (pass = {})",
-                end_time - start_time,
-                self.pass
-            );
+                log::info!(
+                    "compress: Optimizer took {:?} (pass = {})",
+                    end_time - start_time,
+                    self.pass
+                );
+            }
             // let done = dump(&*n);
             // log::debug!("===== Result =====\n{}", done);
         }
@@ -225,12 +230,20 @@ impl VisitMut for Compressor<'_> {
                 "".into()
             };
 
-            let start_time = Instant::now();
+            let start_time = now();
 
             let mut v = dead_branch_remover();
             n.map_with_mut(|n| n.fold_with(&mut v));
 
-            let end_time = Instant::now();
+            if let Some(start_time) = start_time {
+                let end_time = Instant::now();
+
+                log::info!(
+                    "compress: dead_branch_remover took {:?} (pass = {})",
+                    end_time - start_time,
+                    self.pass
+                );
+            }
 
             if cfg!(feature = "debug") {
                 let simplified = dump(&*n);
@@ -244,12 +257,6 @@ impl VisitMut for Compressor<'_> {
                 }
             }
 
-            log::info!(
-                "compress: dead_branch_remover took {:?} (pass = {})",
-                end_time - start_time,
-                self.pass
-            );
-
             self.changed |= v.changed();
         }
 

ecmascript/minifier/src/compress/optimize/conditionals.rs

@@ -681,6 +681,8 @@ impl Optimizer<'_> {
                 if cons.callee.eq_ignore_span(&alt.callee) {
                     if cons.args.as_ref().map(|v| v.len() <= 1).unwrap_or(true)
                         && alt.args.as_ref().map(|v| v.len() <= 1).unwrap_or(true)
+                        && cons.args.as_ref().map(|v| v.len()).unwrap_or(0)
+                            == alt.args.as_ref().map(|v| v.len()).unwrap_or(0)
                         && (cons.args.is_some()
                             && cons
                                 .args
@@ -698,15 +700,17 @@ impl Optimizer<'_> {
                     {
                         let mut args = vec![];
 
-                        args.push(ExprOrSpread {
-                            spread: None,
-                            expr: Box::new(Expr::Cond(CondExpr {
-                                span: DUMMY_SP,
-                                test: test.take(),
-                                cons: cons.args.as_mut().unwrap()[0].expr.take(),
-                                alt: alt.args.as_mut().unwrap()[0].expr.take(),
-                            })),
-                        });
+                        if cons.args.as_ref().map(|v| v.len()).unwrap_or(0) == 1 {
+                            args.push(ExprOrSpread {
+                                spread: None,
+                                expr: Box::new(Expr::Cond(CondExpr {
+                                    span: DUMMY_SP,
+                                    test: test.take(),
+                                    cons: cons.args.as_mut().unwrap()[0].expr.take(),
+                                    alt: alt.args.as_mut().unwrap()[0].expr.take(),
+                                })),
+                            });
+                        }
 
                         log::debug!(
                             "Compreessing if statement into a condiotnal expression of `new` as \

ecmascript/minifier/src/lib.rs

@@ -25,6 +25,7 @@ pub use crate::pass::hygiene::optimize_hygiene;
 use crate::pass::mangle_names::name_mangler;
 use crate::pass::mangle_props::mangle_properties;
 use crate::pass::precompress::precompress_optimizer;
+use crate::util::now;
 use analyzer::analyze;
 use pass::postcompress::postcompress_optimizer;
 use std::time::Instant;
@@ -57,7 +58,7 @@ pub fn optimize(
 ) -> Module {
     let marks = Marks::new();
 
-    let start = Instant::now();
+    let start = now();
     if let Some(defs) = options.compress.as_ref().map(|c| &c.global_defs) {
         // Apply global defs.
         //
@@ -70,12 +71,16 @@ pub fn optimize(
             m.visit_mut_with(&mut global_defs::globals_defs(defs, extra.top_level_mark));
         }
     }
-    log::info!("global_defs took {:?}", Instant::now() - start);
+    if let Some(start) = start {
+        log::info!("global_defs took {:?}", Instant::now() - start);
+    }
 
     if let Some(options) = &options.compress {
-        let start = Instant::now();
+        let start = now();
         m.visit_mut_with(&mut precompress_optimizer(options.clone()));
-        log::info!("precompress took {:?}", Instant::now() - start);
+        if let Some(start) = start {
+            log::info!("precompress took {:?}", Instant::now() - start);
+        }
     }
 
     m.visit_mut_with(&mut unique_marker());
@@ -108,14 +113,18 @@ pub fn optimize(
         t.section("compress");
     }
     if let Some(options) = &options.compress {
-        let start = Instant::now();
+        let start = now();
         m = m.fold_with(&mut compressor(cm.clone(), marks, &options, comments));
-        log::info!("compressor took {:?}", Instant::now() - start);
+        if let Some(start) = start {
+            log::info!("compressor took {:?}", Instant::now() - start);
+        }
         // Again, we don't need to validate ast
 
-        let start = Instant::now();
+        let start = now();
         m.visit_mut_with(&mut postcompress_optimizer(options));
-        log::info!("postcompressor took {:?}", Instant::now() - start);
+        if let Some(start) = start {
+            log::info!("postcompressor took {:?}", Instant::now() - start);
+        }
     }
 
     if let Some(ref mut _t) = timings {

ecmascript/minifier/src/pass/hygiene/mod.rs

@@ -4,6 +4,7 @@ use crate::analyzer::analyze;
 use crate::analyzer::ProgramData;
 use crate::pass::hygiene::analyzer::HygieneAnalyzer;
 use crate::pass::hygiene::analyzer::HygieneData;
+use crate::util::now;
 use swc_common::Mark;
 use swc_common::SyntaxContext;
 use swc_common::DUMMY_SP;
@@ -70,7 +71,7 @@ impl VisitMut for Optimizer {
 
     fn visit_mut_module(&mut self, n: &mut Module) {
         log::info!("hygiene: Analyzing span hygiene");
-        let start = Instant::now();
+        let start = now();
 
         let mut analyzer = HygieneAnalyzer {
             data: &self.data,
@@ -81,13 +82,18 @@ impl VisitMut for Optimizer {
         n.visit_with(&Invalid { span: DUMMY_SP }, &mut analyzer);
         self.hygiene = analyzer.hygiene;
 
-        let end = Instant::now();
-        log::info!("hygiene: Span hygiene analysis took {:?}", end - start);
-        let start = end;
+        if let Some(start) = start {
+            let end = Instant::now();
+            log::info!("hygiene: Span hygiene analysis took {:?}", end - start);
+        }
+        let start = now();
 
         log::info!("hygiene: Optimizing span hygiene");
         n.visit_mut_children_with(self);
-        let end = Instant::now();
-        log::info!("hygiene: Span hygiene optimiation took {:?}", end - start);
+
+        if let Some(start) = start {
+            let end = Instant::now();
+            log::info!("hygiene: Span hygiene optimiation took {:?}", end - start);
+        }
     }
 }

ecmascript/minifier/src/pass/mangle_names/mod.rs

@@ -56,7 +56,15 @@ impl Mangler {
         }
 
         loop {
-            let sym: JsWord = base54(self.n).into();
+            let sym = match base54(self.n) {
+                Some(v) => v,
+                None => {
+                    self.n += 1;
+                    continue;
+                }
+            };
+
+            let sym: JsWord = sym.into();
             self.n += 1;
             if self.preserved_symbols.contains(&sym) {
                 continue;
@@ -75,12 +83,22 @@ impl Mangler {
         let new_sym = if let Some(cached) = self.renamed_private.get(&id) {
             cached.clone()
         } else {
-            let sym: JsWord = base54(self.private_n).into();
-            self.private_n += 1;
+            loop {
+                let sym = match base54(self.private_n) {
+                    Some(v) => v,
+                    None => {
+                        self.private_n += 1;
+                        continue;
+                    }
+                };
 
-            self.renamed_private.insert(id.clone(), sym.clone());
+                let sym: JsWord = sym.into();
+                self.private_n += 1;
 
-            sym
+                self.renamed_private.insert(id.clone(), sym.clone());
+
+                break sym;
+            }
         };
 
         private_name.id.sym = new_sym;

ecmascript/minifier/src/pass/mangle_props.rs

@@ -91,11 +91,20 @@ impl ManglePropertiesState {
             if let Some(cached) = self.cache.get(name) {
                 Some(cached.clone())
             } else {
-                let n = self.n;
-                self.n += 1;
-                let mangled_name: JsWord = base54(n).into();
-                self.cache.insert(name.clone(), mangled_name.clone());
-                Some(mangled_name)
+                loop {
+                    let n = self.n;
+                    self.n += 1;
+                    let sym = match base54(n) {
+                        Some(v) => v,
+                        None => {
+                            continue;
+                        }
+                    };
+
+                    let mangled_name: JsWord = sym.into();
+                    self.cache.insert(name.clone(), mangled_name.clone());
+                    return Some(mangled_name);
+                }
             }
         } else {
             None

ecmascript/minifier/src/timing.rs

@@ -1,6 +1,8 @@
 use std::io::{self, Write};
 use std::time::{Duration, Instant};
 
+use crate::util::now;
+
 /// TOOD: Add timings.
 #[derive(Default, Debug)]
 pub struct Timings {
@@ -18,7 +20,7 @@ impl Timings {
     pub fn section(&mut self, name: &str) {
         self.end_section();
 
-        self.current_section = Some((String::from(name), Instant::now()));
+        self.current_section = now().map(|now| (String::from(name), now));
     }
 
     pub fn end_section(&mut self) {

ecmascript/minifier/src/util/base54.rs

@@ -1,7 +1,10 @@
 const CHARS: &[u8] = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
 
 /// Note: This returns `a` for 0.
-pub(crate) fn base54(mut n: usize) -> String {
+///
+/// Returns [None] if the value is is not a valid ideitifer.
+pub(crate) fn base54(init: usize) -> Option<String> {
+    let mut n = init;
     let mut ret = String::new();
     let mut base = 54;
 
@@ -10,10 +13,21 @@ pub(crate) fn base54(mut n: usize) -> String {
     while n > 0 {
         n -= 1;
 
-        ret.push(CHARS[n % base] as char);
+        let c = CHARS[n % base] as char;
+
+        if ret.is_empty() && c.is_digit(10) {
+            return None;
+        }
+
+        ret.push(c);
+
         n = n / base;
         base = 64;
     }
 
-    ret
+    if ret == "do" {
+        return None;
+    }
+
+    Some(ret)
 }

ecmascript/minifier/src/util/mod.rs

@@ -1,3 +1,5 @@
+use std::time::Instant;
+
 use fxhash::FxHashSet;
 use swc_common::pass::CompilerPass;
 use swc_common::pass::Repeated;
@@ -475,3 +477,11 @@ pub(crate) fn can_end_conditionally(s: &Stmt) -> bool {
 
     can_end(s, true)
 }
+
+pub fn now() -> Option<Instant> {
+    if cfg!(target_arch = "wasm32") {
+        None
+    } else {
+        Some(Instant::now())
+    }
+}

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@swc/core",
-    "version": "1.2.69",
+    "version": "1.2.70",
     "description": "Super-fast alternative for babel",
     "homepage": "https://swc.rs",
     "main": "./index.js",

tests/projects.rs

@@ -715,3 +715,27 @@ fn tests(dir: PathBuf) {
         .map(|_| ())
         .expect("failed");
 }
+
+#[test]
+fn issue_1984() {
+    testing::run_test2(false, |cm, handler| {
+        let c = Compiler::new(cm.clone(), Arc::new(handler));
+        let fm = c.cm.new_source_file(
+            FileName::Anon,
+            "
+            function Set() {}
+            function useSelection(selectionType, derivedHalfSelectedKeys) {
+                return selectionType === 'radio'
+                    ? new Set()
+                    : new Set(derivedHalfSelectedKeys);
+            }
+            "
+            .into(),
+        );
+
+        c.minify(fm, &serde_json::from_str("{}").unwrap()).unwrap();
+
+        Ok(())
+    })
+    .unwrap()
+}

wasm/Cargo.toml

@@ -6,7 +6,7 @@ license = "Apache-2.0 AND MIT"
 name = "wasm"
 publish = false
 repository = "https://github.com/swc-project/swc.git"
-version = "1.2.69"
+version = "1.2.70"
 
 [lib]
 crate-type = ["cdylib"]