wrote more of the compressor and added some tests

test/compress/blocks.js

@@ -0,0 +1,49 @@
+remove_blocks: {
+    input: {
+        {;}
+        foo();
+        {};
+        {
+            {};
+        };
+        bar();
+        {}
+    }
+    expect: {
+        foo();
+        bar();
+    }
+}
+
+keep_some_blocks: {
+    input: {
+        // 1.
+        if (foo) {
+            {{{}}}
+            if (bar) baz();
+            {{}}
+        } else {
+            stuff();
+        }
+
+        // 2.
+        if (foo) {
+            for (var i = 0; i < 5; ++i)
+                if (bar) baz();
+        } else {
+            stuff();
+        }
+    }
+    expect: {
+        // 1.
+        if (foo) {
+            if (bar) baz();
+        } else stuff();
+
+        // 2.
+        if (foo) {
+            for (var i = 0; i < 5; ++i)
+                if (bar) baz();
+        } else stuff();
+    }
+}

test/compress/dead-code.js

@@ -0,0 +1,53 @@
+dead_code_1: {
+    options = {
+        dead_code: true
+    };
+    input: {
+        function f() {
+            a();
+            b();
+            x = 10;
+            return;
+            if (x) {
+                y();
+            }
+        }
+    }
+    expect: {
+        function f() {
+            a();
+            b();
+            x = 10;
+            return;
+        }
+    }
+}
+
+dead_code_2_should_warn: {
+    options = {
+        dead_code: true
+    };
+    input: {
+        function f() {
+            g();
+            x = 10;
+            throw "foo";
+            // completely discarding the `if` would introduce some
+            // bugs.  UglifyJS v1 doesn't deal with this issue.
+            if (x) {
+                y();
+                var x;
+                function g(){};
+            }
+        }
+    }
+    expect: {
+        function f() {
+            g();
+            x = 10;
+            throw "foo";
+            var x;
+            function g(){};
+        }
+    }
+}

test/compress/debugger.js

@@ -0,0 +1,24 @@
+keep_debugger: {
+    options = {
+        drop_debugger: false
+    };
+    input: {
+        debugger;
+    }
+    expect: {
+        debugger;
+    }
+}
+
+drop_debugger: {
+    options = {
+        drop_debugger: true
+    };
+    input: {
+        debugger;
+        if (foo) debugger;
+    }
+    expect: {
+        if (foo);
+    }
+}

test/compress/properties.js

@@ -0,0 +1,25 @@
+keep_properties: {
+    options = {
+        properties: false
+    };
+    input: {
+        a["foo"] = "bar";
+    }
+    expect: {
+        a["foo"] = "bar";
+    }
+}
+
+dot_properties: {
+    options = {
+        properties: true
+    };
+    input: {
+        a["foo"] = "bar";
+        a["if"] = "if";
+    }
+    expect: {
+        a.foo = "bar";
+        a["if"] = "if";
+    }
+}

test/compress/sequences.js

@@ -0,0 +1,60 @@
+make_sequences_1: {
+    options = {
+        sequences: true
+    };
+    input: {
+        foo();
+        bar();
+        baz();
+    }
+    expect: {
+        foo(),bar(),baz();
+    }
+}
+
+make_sequences_2: {
+    options = {
+        sequences: true
+    };
+    input: {
+        if (boo) {
+            foo();
+            bar();
+            baz();
+        } else {
+            x();
+            y();
+            z();
+        }
+    }
+    expect: {
+        if (boo) foo(),bar(),baz();
+        else x(),y(),z();
+    }
+}
+
+make_sequences_3: {
+    options = {
+        sequences: true
+    };
+    input: {
+        function f() {
+            foo();
+            bar();
+            return baz();
+        }
+        function g() {
+            foo();
+            bar();
+            throw new Error();
+        }
+    }
+    expect: {
+        function f() {
+            return foo(), bar(), baz();
+        }
+        function g() {
+            throw foo(), bar(), new Error();
+        }
+    }
+}

test/run-tests.js

@@ -0,0 +1,144 @@
+#! /usr/bin/env node
+
+var U = require("../tools/node");
+var path = require("path");
+var fs = require("fs");
+var assert = require("assert");
+var sys = require("util");
+
+var tests_dir = path.dirname(module.filename);
+
+run_compress_tests();
+
+/* -----[ utils ]----- */
+
+function tmpl() {
+    return U.string_template.apply(this, arguments);
+}
+
+function log() {
+    var txt = tmpl.apply(this, arguments);
+    sys.puts(txt);
+}
+
+function log_directory(dir) {
+    log("--- Entering [{dir}]", { dir: dir });
+}
+
+function log_start_file(file) {
+    log("*** {file}", { file: file });
+}
+
+function log_test(name) {
+    log("    Running test [{name}]", { name: name });
+}
+
+function find_test_files(dir) {
+    var files = fs.readdirSync(dir).filter(function(name){
+        return /\.js$/i.test(name);
+    });
+    return files;
+}
+
+function test_directory(dir) {
+    return path.resolve(tests_dir, dir);
+}
+
+function run_compress_tests() {
+    var dir = test_directory("compress");
+    log_directory("compress");
+    var files = find_test_files(dir);
+    function test_file(file) {
+        log_start_file(file);
+        function test_case(test) {
+            log_test(test.name);
+            var cmp = new U.Compressor(test.options || {}, true);
+            var expect = make_code(test.expect, false);
+            var output = make_code(test.input.squeeze(cmp), false);
+            if (expect != output) {
+                log("!!! failed\n---INPUT---\n{input}\n---OUTPUT---\n{output}\n---EXPECTED---\n{expected}\n\n", {
+                    input: make_code(test.input),
+                    output: output,
+                    expected: expect
+                });
+            }
+        }
+        var tests = parse_test(path.resolve(dir, file));
+        for (var i in tests) if (tests.hasOwnProperty(i)) {
+            test_case(tests[i]);
+        }
+    }
+    files.forEach(function(file){
+        test_file(file);
+    });
+}
+
+function parse_test(file) {
+    var script = fs.readFileSync(file, "utf8");
+    var ast = U.parse(script);
+    var tests = {};
+    var tw = new U.TreeWalker(function(node, descend){
+        if (node instanceof U.AST_LabeledStatement
+            && tw.parent() instanceof U.AST_Toplevel) {
+            var name = node.label.name;
+            tests[name] = get_one_test(name, node.statement);
+            return true;
+        }
+        if (!(node instanceof U.AST_Toplevel)) croak(node);
+    });
+    ast.walk(tw);
+    return tests;
+
+    function croak(node) {
+        throw new Error(tmpl("Can't understand test file {file} [{line},{col}]\n{code}", {
+            file: file,
+            line: node.start.line,
+            col: node.start.col,
+            code: make_code(node, false)
+        }));
+    }
+
+    function get_one_test(name, block) {
+        var test = { name: name, options: {} };
+        var tw = new U.TreeWalker(function(node, descend){
+            if (node instanceof U.AST_Assign) {
+                if (!(node.left instanceof U.AST_SymbolRef)) {
+                    croak(node);
+                }
+                var name = node.left.name;
+                test[name] = evaluate(node.right);
+                return true;
+            }
+            if (node instanceof U.AST_LabeledStatement) {
+                assert.ok(
+                    node.label.name == "input" || node.label.name == "expect",
+                    tmpl("Unsupported label {name} [{line},{col}]", {
+                        name: node.label.name,
+                        line: node.label.start.line,
+                        col: node.label.start.col
+                    })
+                );
+                var stat = node.statement;
+                if (stat instanceof U.AST_BlockStatement)
+                    stat.required = 1;
+                test[node.label.name] = stat;
+                return true;
+            }
+        });
+        block.walk(tw);
+        return test;
+    };
+}
+
+function make_code(ast, beautify) {
+    if (arguments.length == 1) beautify = true;
+    var stream = U.OutputStream({ beautify: beautify });
+    ast.print(stream);
+    return stream.get();
+}
+
+function evaluate(code) {
+    if (code instanceof U.AST_Node)
+        code = make_code(code);
+    return new Function("return(" + code + ")")();
+}