Skip to content
New issue

Have a question about this project? # for a free GitHub account to open an issue and contact its maintainers and the community.

#

By clicking “#”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? # to your account

Jump to bottom

Minify some Logical Expression patterns #227

Merged
merged 2 commits into from
Nov 3, 2016
Merged

Minify some Logical Expression patterns #227

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
4fbbd40
Minify some Logical Expression patterns
boopathi Oct 26, 2016
4b1c29d
Memoize evaluate results, add a few more tests, upgrade jest
boopathi Oct 27, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions package.json
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@
},
"devDependencies": {
"babel-core": "^6.18.0",
"babel-jest": "^14.1.0",
"babel-jest": "^16.0.0",
"babel-plugin-transform-es2015-block-scoping": "^6.18.0",
"babel-preset-es2015": "^6.18.0",
"babel-traverse": "^6.16.0",
Expand All @@ -43,7 +43,7 @@
"gulp-babel": "^6.1.2",
"gulp-newer": "^1.1.0",
"gulp-util": "^3.0.7",
"jest-cli": "^14.1.0",
"jest-cli": "^16.0.2",
"lerna": "2.0.0-beta.26",
"lerna-changelog": "^0.2.1",
"through2": "^2.0.1",
Expand Down
157 changes: 157 additions & 0 deletions packages/babel-plugin-minify-simplify/__tests__/simplify-test.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2107,6 +2107,163 @@ describe("simplify-plugin", () => {
expect(transform(source)).toBe(expected);
});

// From UglifyJS
it("should simplify logical expression of the following forms of &&", () => {
// compress to right
let sources = unpad(`
a = true && foo
a = 1 && console.log("asdf")
a = 4 * 2 && foo()
a = 10 == 10 && foo() + bar()
a = "foo" && foo()
a = 1 + "a" && foo / 10
a = -1 && 5 << foo
a = 6 && 10
a = !NaN && foo()
`).split("\n");

let expected = unpad(`
a = foo;
a = console.log("asdf");
a = foo();
a = foo() + bar();
a = foo();
a = foo / 10;
a = 5 << foo;
a = 10;
a = foo();
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(expected);

// compress to left
sources = unpad(`
a = false && bar
a = NaN && console.log("a")
a = 0 && bar()
a = undefined && foo(bar)
a = 3 * 3 - 9 && bar(foo)
a = 9 == 10 && foo()
a = !"string" && foo % bar
a = 0 && 7
`).split("\n");

expected = unpad(`
a = false;
a = NaN;
a = 0;
a = undefined;
a = 0;
a = false;
a = false;
a = 0;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(expected);

// don't compress
sources = unpad(`
a = foo() && true;
a = console.log && 3 + 8;
a = foo + bar + 5 && "a";
a = 4 << foo && -1.5;
a = bar() && false;
a = foo() && 0;
a = bar() && NaN;
a = foo() && null;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(sources);
});

it("should simplify logical expression of the following forms of ||", () => {
// compress to left
let sources = unpad(`
a = true || condition;
a = 1 || console.log("a");
a = 2 * 3 || 2 * condition;
a = 5 == 5 || condition + 3;
a = "string" || 4 - condition;
a = 5 + "" || condition / 5;
a = -4.5 || 6 << condition;
a = 6 || 7;
`).split("\n");

let expected = unpad(`
a = true;
a = 1;
a = 6;
a = true;
a = "string";
a = "5";
a = -4.5;
a = 6;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(expected);

sources = unpad(`
a = false || condition;
a = 0 || console.log("b");
a = NaN || console.log("c");
a = undefined || 2 * condition;
a = null || condition + 3;
a = 2 * 3 - 6 || 4 - condition;
a = 10 == 7 || condition / 5;
a = !"string" || 6 % condition;
a = null || 7;
`).split("\n");

expected = unpad(`
a = condition;
a = console.log("b");
a = console.log("c");
a = 2 * condition;
a = condition + 3;
a = 4 - condition;
a = condition / 5;
a = 6 % condition;
a = 7;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(expected);

// don't compress
sources = unpad(`
a = condition || true;
a = console.log("a") || 2;
a = 4 - condition || "string";
a = 6 << condition || -4.5;
a = condition || false;
a = console.log("b") || NaN;
a = console.log("c") || 0;
a = 2 * condition || undefined;
a = condition + 3 || null;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(sources);
});

it("should transform complex logical expressions", () => {
let sources = unpad(`
a = true && 1 && foo
a = 1 && 4 * 2 && console.log("asdf")
a = 4 * 2 && NaN && foo()
a = 10 == 11 || undefined && foo() + bar() && bar()
a = -1 && undefined || 5 << foo
`).split("\n");

let expected = unpad(`
a = foo;
a = console.log("asdf");
a = NaN;
a = undefined;
a = 5 << foo;
`).split("\n");

expect(sources.map((s) => transform(s))).toEqual(expected);
});

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

test cases for nested logical expressions?

// https://github.com/babel/babili/issues/115
it("should transform impure conditional statements correctly - issue#115", () => {
const source = unpad(`
Expand Down
73 changes: 73 additions & 0 deletions packages/babel-plugin-minify-simplify/src/index.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,9 @@ module.exports = ({ types: t }) => {
const or = (a, b) => t.logicalExpression("||", a, b);
const and = (a, b) => t.logicalExpression("&&", a, b);

const OP_AND = (input) => input === "&&";
const OP_OR = (input) => input === "||";

return {
name: "minify-simplify",
visitor: {
Expand Down Expand Up @@ -124,6 +127,73 @@ module.exports = ({ types: t }) => {
],
},

LogicalExpression: {
exit(path) {
// cache of path.evaluate()
const evaluateMemo = new Map;

const TRUTHY = (input) => {
// !NaN and !undefined are truthy
// separate check here as they are considered impure by babel
if (input.isUnaryExpression() && input.get("argument").isIdentifier()) {
if (input.node.argument.name === "NaN" || input.node.argument.name === "undefined") {
return true;
}
}
const evalResult = input.evaluate();
evaluateMemo.set(input, evalResult);
return evalResult.confident && input.isPure() && evalResult.value;
};

const FALSY = (input) => {
// NaN and undefined are falsy
// separate check here as they are considered impure by babel
if (input.isIdentifier()) {
if (input.node.name === "NaN" || input.node.name === "undefined") {
return true;
}
}
const evalResult = input.evaluate();
evaluateMemo.set(input, evalResult);
return evalResult.confident && input.isPure() && !evalResult.value;
};

const {
Expression: EX
} = types;

// Convention:
// [left, operator, right, handler(leftNode, rightNode)]
const matcher = new PatternMatch([
[TRUTHY, OP_AND, EX, (l, r) => r],
[FALSY, OP_AND, EX, (l) => l],
[TRUTHY, OP_OR, EX, (l) => l],
[FALSY, OP_OR, EX, (l, r) => r]
]);

const left = path.get("left");
const right = path.get("right");
const operator = path.node.operator;

const result = matcher.match(
[left, operator, right],
isPatternMatchesPath
);

if (result.match) {
// here we are sure that left.evaluate is always confident becuase
// it satisfied one of TRUTHY/FALSY paths
let value;
if (evaluateMemo.has(left)) {
value = evaluateMemo.get(left).value;
} else {
value = left.evaluate().value;
}
path.replaceWith(result.value(t.valueToNode(value), right.node));
}
}
},

ConditionalExpression: {
enter: [
// !foo ? 'foo' : 'bar' -> foo ? 'bar' : 'foo'
Expand Down Expand Up @@ -1378,6 +1448,9 @@ module.exports = ({ types: t }) => {
}
return false;
}
if (typeof patternValue === "function") {
return patternValue(inputPath);
}
if (isNodeOfType(inputPath.node, patternValue)) return true;
let evalResult = inputPath.evaluate();
if (!evalResult.confident || !inputPath.isPure()) return false;
Expand Down
2 changes: 2 additions & 0 deletions packages/babel-plugin-minify-simplify/src/pattern-match.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@ module.exports = class PatternMatch {
result.value = current;
break;
}
} else {
break;
}
}
return result;
Expand Down