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speed up --reduce-test (#3726)
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- avoid pathological test case branches via adaptive time-out
- use initial test case elapsed time to adjust maximum time-out
- index output cache using hash instead of raw source
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@alexlamsl
alexlamsl committed Feb 17, 2020
1 parent c13caf4 commit 53517db
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Showing 2 changed files with 86 additions and 39 deletions.
32 changes: 30 additions & 2 deletions test/mocha/reduce.js
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Expand Up @@ -2,6 +2,7 @@ var assert = require("assert");
var exec = require("child_process").exec;
var fs = require("fs");
var reduce_test = require("../reduce");
var semver = require("semver");

function read(path) {
return fs.readFileSync(path, "utf8");
Expand Down Expand Up @@ -43,7 +44,6 @@ describe("test/reduce.js", function() {
"// {",
'// "toplevel": true',
"// }",
"",
].join("\n"));
});
it("Should handle test result of NaN", function() {
Expand All @@ -55,7 +55,6 @@ describe("test/reduce.js", function() {
'// "compress": {},',
'// "mangle": false',
"// }",
"",
].join("\n"));
});
it("Should print correct output for irreducible test case", function() {
Expand Down Expand Up @@ -136,4 +135,33 @@ describe("test/reduce.js", function() {
"// }",
].join("\n"));
});
it("Should reduce infinite loops with reasonable performance", function() {
if (semver.satisfies(process.version, "0.10")) return;
this.timeout(120000);
var code = [
"var a = 9007199254740992, b = 1;",
"",
"while (a++ + (1 - b) < a) {",
" 0;",
"}",
].join("\n");
var result = reduce_test(code, {
compress: {
unsafe_math: true,
},
mangle: false,
});
if (result.error) throw result.error;
assert.strictEqual(result.code.replace(/ timed out after [0-9]+ms/, " timed out."), [
code,
"// output: ",
"// minify: Error: Script execution timed out.",
"// options: {",
'// "compress": {',
'// "unsafe_math": true',
"// },",
'// "mangle": false',
"// }",
].join("\n"));
});
});
93 changes: 56 additions & 37 deletions test/reduce.js
View file
@@ -1,3 +1,4 @@
var crypto = require("crypto");
var U = require("./node");
var List = U.List;
var sandbox = require("./sandbox");
Expand All @@ -17,21 +18,32 @@ var sandbox = require("./sandbox");
// Returns a `minify` result object with an additonal boolean property `reduced`.

module.exports = function reduce_test(testcase, minify_options, reduce_options) {
if (testcase instanceof U.AST_Node) testcase = testcase.print_to_string();
minify_options = minify_options || { compress: {}, mangle: false };
reduce_options = reduce_options || {};
var max_iterations = reduce_options.max_iterations || 1000;
var max_timeout = reduce_options.max_timeout || 15000;
var max_timeout = reduce_options.max_timeout || 10000;
var verbose = reduce_options.verbose;
var minify_options_json = JSON.stringify(minify_options, null, 2);
var timeout = 1000; // start with a low timeout
var result_cache = Object.create(null);
var differs;

if (testcase instanceof U.AST_Node) testcase = testcase.print_to_string();

// the initial timeout to assess the viability of the test case must be large
if (differs = producesDifferentResultWhenMinified(result_cache, testcase, minify_options, max_timeout)) {
if (differs.error) return differs;
var differs = producesDifferentResultWhenMinified(result_cache, testcase, minify_options, max_timeout);

if (!differs) {
// same stdout result produced when minified
return {
code: "// Can't reproduce test failure with minify options provided:"
+ "\n// " + to_comment(minify_options_json)
};
} else if (differs.timed_out) {
return {
code: "// Can't reproduce test failure within " + max_timeout + "ms:"
+ "\n// " + to_comment(minify_options_json)
};
} else if (differs.error) {
return differs;
} else {
max_timeout = Math.min(100 * differs.elapsed, max_timeout);
// Replace expressions with constants that will be parsed into
// AST_Nodes as required. Each AST_Node has its own permutation count,
// so these replacements can't be shared.
Expand Down Expand Up @@ -400,15 +412,11 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
console.error("*** Discarding permutation and continuing.");
continue;
}
var diff = producesDifferentResultWhenMinified(result_cache, code, minify_options, timeout);
var diff = producesDifferentResultWhenMinified(result_cache, code, minify_options, max_timeout);
if (diff) {
if (diff.timed_out) {
// can't trust the validity of `code_ast` and `code` when timed out.
// no harm done - just ignore latest change and continue iterating.
if (timeout < max_timeout) {
timeout += 250;
result_cache = Object.create(null);
}
} else if (diff.error) {
// something went wrong during minify() - could be malformed AST or genuine bug.
// no harm done - just log code & error, ignore latest change and continue iterating.
Expand All @@ -433,23 +441,23 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
console.error("// reduce test pass " + pass + ": " + testcase.length + " bytes");
}
}
testcase += "\n// output: " + to_comment(differs.unminified_result)
+ "\n// minify: " + to_comment(differs.minified_result)
+ "\n// options: " + to_comment(minify_options_json);
} else {
// same stdout result produced when minified
testcase = "// Can't reproduce test failure with minify options provided:"
+ "\n// " + to_comment(minify_options_json);
testcase = U.minify(testcase, {
compress: false,
mangle: false,
output: {
beautify: true,
braces: true,
comments: true,
},
});
testcase.code += [
"",
"// output: " + to_comment(differs.unminified_result),
"// minify: " + to_comment(differs.minified_result),
"// options: " + to_comment(minify_options_json),
].join("\n").replace(/\u001b\[\d+m/g, "");
return testcase;
}
return U.minify(testcase.replace(/\u001b\[\d+m/g, ""), {
compress: false,
mangle: false,
output: {
beautify: true,
braces: true,
comments: true,
}
});
};

function to_comment(value) {
Expand Down Expand Up @@ -489,6 +497,10 @@ function is_error(result) {
return typeof result == "object" && typeof result.name == "string" && typeof result.message == "string";
}

function is_timed_out(result) {
return is_error(result) && /timed out/.test(result);
}

function is_statement(node) {
return node instanceof U.AST_Statement && !(node instanceof U.AST_Function);
}
Expand Down Expand Up @@ -519,23 +531,30 @@ function to_statement(node) {
}

function run_code(result_cache, code, toplevel, timeout) {
return result_cache[code] || (result_cache[code] = sandbox.run_code(code, toplevel, timeout));
var key = crypto.createHash("sha1").update(code).digest("base64");
return result_cache[key] || (result_cache[key] = sandbox.run_code(code, toplevel, timeout));
}

function producesDifferentResultWhenMinified(result_cache, code, minify_options, timeout) {
function producesDifferentResultWhenMinified(result_cache, code, minify_options, max_timeout) {
var minified = U.minify(code, minify_options);
if (minified.error) return minified;

var toplevel = minify_options.toplevel;
var unminified_result = run_code(result_cache, code, toplevel, timeout);
if (/timed out/i.test(unminified_result)) return false;

var elapsed = Date.now();
var unminified_result = run_code(result_cache, code, toplevel, max_timeout);
elapsed = Date.now() - elapsed;
var timeout = Math.min(100 * elapsed, max_timeout);
var minified_result = run_code(result_cache, minified.code, toplevel, timeout);
if (/timed out/i.test(minified_result)) return { timed_out: true };

return !sandbox.same_stdout(unminified_result, minified_result) ? {
if (sandbox.same_stdout(unminified_result, minified_result)) {
return is_timed_out(unminified_result) && is_timed_out(minified_result) && {
timed_out: true,
};
}
return {
unminified_result: unminified_result,
minified_result: minified_result,
} : false;
elapsed: elapsed,
};
}
Error.stackTraceLimit = Infinity;

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