feat(swc): Expose minifier api (#1978)

swc_ecma_codegen:
 - Fix codegen of imports when minification is enabled.

swc_ecma_minifier:
 - Mangle identifiers used by imports.

swc:
 - Support specifing `jsc.minify`. (#704, #1371)

swc/node:
 - Add `.minify()`.
 - Add `.minifySync()`.

swc/wasm:
 - Add `.minifySync()`.

Author: kdy1

Cargo.lock

@@ -9,7 +9,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.32.0"
+version = "0.33.0"
 
 [lib]
 name = "swc"
@@ -35,6 +35,7 @@ swc_ecma_ast = {version = "0.49.0", path = "./ecmascript/ast"}
 swc_ecma_codegen = {version = "0.64.0", path = "./ecmascript/codegen"}
 swc_ecma_ext_transforms = {version = "0.23.0", path = "./ecmascript/ext-transforms"}
 swc_ecma_loader = {version = "0.12.0", path = "./ecmascript/loader", features = ["lru", "node", "tsc"]}
+swc_ecma_minifier = {version = "0.16.0", path = "./ecmascript/minifier"}
 swc_ecma_parser = {version = "0.65.0", path = "./ecmascript/parser"}
 swc_ecma_preset_env = {version = "0.31.0", path = "./ecmascript/preset-env"}
 swc_ecma_transforms = {version = "0.61.0", path = "./ecmascript/transforms", features = [
@@ -45,6 +46,7 @@ swc_ecma_transforms = {version = "0.61.0", path = "./ecmascript/transforms", fea
   "react",
   "typescript",
 ]}
+swc_ecma_transforms_base = {version = "0.24.1", path = "./ecmascript/transforms/base"}
 swc_ecma_utils = {version = "0.41.0", path = "./ecmascript/utils"}
 swc_ecma_visit = {version = "0.35.0", path = "./ecmascript/visit"}
 swc_node_base = {version = "0.2.0", path = "./node/base"}

Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc_ecmascript"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.49.0"
+version = "0.50.0"
 
 [package.metadata.docs.rs]
 all-features = true
@@ -34,7 +34,7 @@ typescript = ["typescript-parser", "swc_ecma_transforms/typescript"]
 swc_ecma_ast = {version = "0.49.0", path = "./ast"}
 swc_ecma_codegen = {version = "0.64.0", path = "./codegen", optional = true}
 swc_ecma_dep_graph = {version = "0.33.0", path = "./dep-graph", optional = true}
-swc_ecma_minifier = {version = "0.15.0", path = "./minifier", optional = true}
+swc_ecma_minifier = {version = "0.16.0", path = "./minifier", optional = true}
 swc_ecma_parser = {version = "0.65.0", path = "./parser", optional = true, default-features = false}
 swc_ecma_transforms = {version = "0.61.0", path = "./transforms", optional = true}
 swc_ecma_utils = {version = "0.41.0", path = "./utils", optional = true}

ecmascript/Cargo.toml

@@ -7,7 +7,7 @@ include = ["Cargo.toml", "src/**/*.rs"]
 license = "Apache-2.0/MIT"
 name = "swc_ecma_codegen"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.64.2"
+version = "0.64.3"
 
 [dependencies]
 bitflags = "1"

ecmascript/codegen/Cargo.toml

@@ -115,7 +115,9 @@ impl<'a> Emitter<'a> {
 
         self.emit_trailing_comments_of_pos(node.span().hi, true, true)?;
 
-        self.wr.write_line()?;
+        if !self.cfg.minify {
+            self.wr.write_line()?;
+        }
     }
 
     #[emitter]
@@ -190,7 +192,7 @@ impl<'a> Emitter<'a> {
 
         if specifiers.is_empty() {
             if emitted_ns || emitted_default {
-                formatting_space!();
+                space!();
                 keyword!("from");
                 formatting_space!();
             }

ecmascript/codegen/src/lib.rs

@@ -92,7 +92,7 @@ mod tests {
     fn import() {
         assert_min(
             "import colors, { color } from 'patterns/colors';",
-            "import colors,{color}from'patterns/colors';",
+            "import colors,{color}from'patterns/colors'",
         );
         assert_pretty(
             "import colors, { color } from 'patterns/colors';",

ecmascript/codegen/src/stmt.rs

@@ -231,7 +231,7 @@ fn empty_named_export() {
 fn empty_named_export_min() {
     test_from_to_custom_config(
         "export { }",
-        "export{};",
+        "export{}",
         Config { minify: true },
         Default::default(),
     );
@@ -246,7 +246,7 @@ fn empty_named_export_from() {
 fn empty_named_export_from_min() {
     test_from_to_custom_config(
         "export { } from 'foo';",
-        "export{}from'foo';",
+        "export{}from'foo'",
         Config { minify: true },
         Default::default(),
     );
@@ -261,7 +261,7 @@ fn named_export_from() {
 fn named_export_from_min() {
     test_from_to_custom_config(
         "export { bar } from 'foo';",
-        "export{bar}from'foo';",
+        "export{bar}from'foo'",
         Config { minify: true },
         Default::default(),
     );
@@ -284,7 +284,7 @@ fn export_namespace_from() {
 fn export_namespace_from_min() {
     test_from_to_custom_config(
         "export * as Foo from 'foo';",
-        "export*as Foo from'foo';",
+        "export*as Foo from'foo'",
         Config { minify: true },
         Syntax::Es(EsConfig {
             export_namespace_from: true,
@@ -310,7 +310,7 @@ fn named_and_namespace_export_from() {
 fn named_and_namespace_export_from_min() {
     test_from_to_custom_config(
         "export * as Foo, { bar } from 'foo';",
-        "export*as Foo,{bar}from'foo';",
+        "export*as Foo,{bar}from'foo'",
         Config { minify: true },
         Syntax::Es(EsConfig {
             export_namespace_from: true,

ecmascript/codegen/src/tests.rs

@@ -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 = "0.15.0"
+version = "0.16.0"
 
 [features]
 debug = []

ecmascript/minifier/Cargo.toml

@@ -482,6 +482,12 @@ impl Visit for UsageAnalyzer {
         }
     }
 
+    fn visit_fn_decl(&mut self, n: &FnDecl, _: &dyn Node) {
+        self.declare_decl(&n.ident, true, None, true);
+
+        n.visit_children_with(self);
+    }
+
     fn visit_fn_expr(&mut self, n: &FnExpr, _: &dyn Node) {
         n.visit_children_with(self);
 
@@ -494,12 +500,6 @@ impl Visit for UsageAnalyzer {
         }
     }
 
-    fn visit_fn_decl(&mut self, n: &FnDecl, _: &dyn Node) {
-        self.declare_decl(&n.ident, true, None, true);
-
-        n.visit_children_with(self);
-    }
-
     fn visit_for_in_stmt(&mut self, n: &ForInStmt, _: &dyn Node) {
         n.right.visit_with(n, self);
 
@@ -584,6 +584,18 @@ impl Visit for UsageAnalyzer {
         n.alt.visit_with(n, &mut *self.with_ctx(ctx));
     }
 
+    fn visit_import_default_specifier(&mut self, n: &ImportDefaultSpecifier, _: &dyn Node) {
+        self.declare_decl(&n.local, true, None, false);
+    }
+
+    fn visit_import_named_specifier(&mut self, n: &ImportNamedSpecifier, _: &dyn Node) {
+        self.declare_decl(&n.local, true, None, false);
+    }
+
+    fn visit_import_star_as_specifier(&mut self, n: &ImportStarAsSpecifier, _: &dyn Node) {
+        self.declare_decl(&n.local, true, None, false);
+    }
+
     fn visit_member_expr(&mut self, e: &MemberExpr, _: &dyn Node) {
         {
             let ctx = Ctx {

ecmascript/minifier/src/analyzer/mod.rs

@@ -1,11 +1,11 @@
 //! Compatibility for terser config.
 
-use crate::option::PureGetterOption;
-
+use super::true_by_default;
 use super::CompressOptions;
 use super::TopLevelOptions;
+use crate::option::PureGetterOption;
 use fxhash::FxHashMap;
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use swc_atoms::JsWord;
 use swc_common::input::SourceFileInput;
@@ -18,15 +18,21 @@ use swc_ecma_parser::lexer::Lexer;
 use swc_ecma_parser::Parser;
 use swc_ecma_utils::drop_span;
 
-#[derive(Debug, Clone, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserEcmaVersion {
     Num(usize),
     Str(String),
 }
 
-#[derive(Debug, Clone, Deserialize)]
+impl Default for TerserEcmaVersion {
+    fn default() -> Self {
+        Self::Num(5)
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserPureGetterOption {
@@ -42,39 +48,39 @@ impl Default for TerserPureGetterOption {
     }
 }
 
-#[derive(Debug, Clone, Copy, Deserialize)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserInlineOption {
     Bool(bool),
     Num(u8),
 }
 
-#[derive(Debug, Clone, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserTopLevelOptions {
     Bool(bool),
     Str(String),
 }
 
-#[derive(Debug, Clone, Copy, Deserialize)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserSequenceOptions {
     Bool(bool),
     Num(u8),
 }
 
-#[derive(Debug, Clone, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 #[serde(untagged)]
 pub enum TerserTopRetainOption {
     Str(String),
     Seq(Vec<JsWord>),
 }
 
-#[derive(Debug, Clone, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct TerserCompressorOptions {
     #[serde(default)]
@@ -104,7 +110,7 @@ pub struct TerserCompressorOptions {
     #[serde(default)]
     pub dead_code: bool,
 
-    #[serde(default)]
+    #[serde(default = "true_by_default")]
     pub defaults: bool,
 
     #[serde(default)]
@@ -242,6 +248,67 @@ pub struct TerserCompressorOptions {
     pub module: bool,
 }
 
+impl Default for TerserCompressorOptions {
+    fn default() -> Self {
+        Self {
+            arguments: Default::default(),
+            arrows: Default::default(),
+            booleans: Default::default(),
+            booleans_as_integers: Default::default(),
+            collapse_vars: Default::default(),
+            comparisons: Default::default(),
+            computed_props: Default::default(),
+            conditionals: Default::default(),
+            dead_code: Default::default(),
+            defaults: true,
+            directives: Default::default(),
+            drop_console: Default::default(),
+            drop_debugger: Default::default(),
+            ecma: Default::default(),
+            evaluate: Default::default(),
+            expression: Default::default(),
+            global_defs: Default::default(),
+            hoist_funs: Default::default(),
+            hoist_props: Default::default(),
+            hoist_vars: Default::default(),
+            ie8: Default::default(),
+            if_return: Default::default(),
+            inline: Default::default(),
+            join_vars: Default::default(),
+            keep_classnames: Default::default(),
+            keep_fargs: Default::default(),
+            keep_fnames: Default::default(),
+            keep_infinity: Default::default(),
+            loops: Default::default(),
+            negate_iife: Default::default(),
+            passes: Default::default(),
+            properties: Default::default(),
+            pure_getters: Default::default(),
+            pure_funcs: Default::default(),
+            reduce_funcs: Default::default(),
+            reduce_vars: Default::default(),
+            sequences: Default::default(),
+            side_effects: Default::default(),
+            switches: Default::default(),
+            top_retain: Default::default(),
+            toplevel: Default::default(),
+            typeofs: Default::default(),
+            unsafe_passes: Default::default(),
+            unsafe_arrows: Default::default(),
+            unsafe_comps: Default::default(),
+            unsafe_function: Default::default(),
+            unsafe_math: Default::default(),
+            unsafe_symbols: Default::default(),
+            unsafe_methods: Default::default(),
+            unsafe_proto: Default::default(),
+            unsafe_regexp: Default::default(),
+            unsafe_undefined: Default::default(),
+            unused: Default::default(),
+            module: Default::default(),
+        }
+    }
+}
+
 fn ecma_default() -> TerserEcmaVersion {
     TerserEcmaVersion::Num(5)
 }