feat: enhance the treehshaking for unary expression (#5775)

* enhance the treehshaking for unary expression * simplify the number string * without considering BigInt * retain boolean and undefined && slightly improve performance
rollup · Jan 6, 2025 · d3e2bf7 · d3e2bf7
1 parent 27216d8
commit d3e2bf7
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Showing 12 changed files with 187 additions and 47 deletions.
diff --git a/src/ast/nodes/UnaryExpression.ts b/src/ast/nodes/UnaryExpression.ts
@@ -1,13 +1,22 @@
+import type MagicString from 'magic-string';
+import type { RenderOptions } from '../../utils/renderHelpers';
 import type { DeoptimizableEntity } from '../DeoptimizableEntity';
-import type { HasEffectsContext } from '../ExecutionContext';
+import type { HasEffectsContext, InclusionContext } from '../ExecutionContext';
 import type { NodeInteraction } from '../NodeInteractions';
 import { INTERACTION_ACCESSED, NODE_INTERACTION_UNKNOWN_ASSIGNMENT } from '../NodeInteractions';
-import { EMPTY_PATH, type ObjectPath, type PathTracker } from '../utils/PathTracker';
+import {
+	EMPTY_PATH,
+	type ObjectPath,
+	type PathTracker,
+	SHARED_RECURSION_TRACKER
+} from '../utils/PathTracker';
 import Identifier from './Identifier';
 import type { LiteralValue } from './Literal';
 import type * as NodeType from './NodeType';
 import { Flag, isFlagSet, setFlag } from './shared/BitFlags';
+import type { InclusionOptions } from './shared/Expression';
 import { type LiteralValueOrUnknown, UnknownValue } from './shared/Expression';
+import type { IncludeChildren } from './shared/Node';
 import { type ExpressionNode, NodeBase } from './shared/Node';
 
 const unaryOperators: Record<string, (value: LiteralValue) => LiteralValueOrUnknown> = {
@@ -20,10 +29,13 @@ const unaryOperators: Record<string, (value: LiteralValue) => LiteralValueOrUnkn
 	'~': value => ~(value as NonNullable<LiteralValue>)
 };
 
+const UNASSIGNED = Symbol('Unassigned');
+
 export default class UnaryExpression extends NodeBase {
 	declare argument: ExpressionNode;
 	declare operator: '!' | '+' | '-' | 'delete' | 'typeof' | 'void' | '~';
 	declare type: NodeType.tUnaryExpression;
+	renderedLiteralValue: string | typeof UnknownValue | typeof UNASSIGNED = UNASSIGNED;
 
 	get prefix(): boolean {
 		return isFlagSet(this.flags, Flag.prefix);
@@ -32,6 +44,10 @@ export default class UnaryExpression extends NodeBase {
 		this.flags = setFlag(this.flags, Flag.prefix, value);
 	}
 
+	deoptimizeCache(): void {
+		this.renderedLiteralValue = UnknownValue;
+	}
+
 	getLiteralValueAtPath(
 		path: ObjectPath,
 		recursionTracker: PathTracker,
@@ -69,4 +85,62 @@ export default class UnaryExpression extends NodeBase {
 			this.scope.context.requestTreeshakingPass();
 		}
 	}
+
+	getRenderedLiteralValue(includeChildrenRecursively: IncludeChildren) {
+		if (this.renderedLiteralValue !== UNASSIGNED) return this.renderedLiteralValue;
+		return (this.renderedLiteralValue = includeChildrenRecursively
+			? UnknownValue
+			: getSimplifiedLiterals(
+					this.getLiteralValueAtPath(EMPTY_PATH, SHARED_RECURSION_TRACKER, this)
+				));
+	}
+
+	include(
+		context: InclusionContext,
+		includeChildrenRecursively: IncludeChildren,
+		_options?: InclusionOptions
+	): void {
+		if (!this.deoptimized) this.applyDeoptimizations();
+		this.included = true;
+		if (
+			typeof this.getRenderedLiteralValue(includeChildrenRecursively) === 'symbol' ||
+			this.argument.shouldBeIncluded(context)
+		) {
+			this.argument.include(context, includeChildrenRecursively);
+			this.renderedLiteralValue = UnknownValue;
+		}
+	}
+
+	render(code: MagicString, options: RenderOptions) {
+		if (typeof this.renderedLiteralValue === 'symbol') {
+			super.render(code, options);
+		} else {
+			code.overwrite(this.start, this.end, this.renderedLiteralValue);
+		}
+	}
+}
+
+function getSimplifiedLiterals(value: unknown) {
+	if (value === undefined || typeof value === 'boolean') {
+		return String(value);
+	}
+	if (typeof value === 'string') {
+		return JSON.stringify(value);
+	}
+	if (typeof value === 'number') {
+		return getSimplifiedNumber(value);
+	}
+	return UnknownValue;
+}
+
+function getSimplifiedNumber(value: number) {
+	if (Object.is(-0, value)) {
+		return '-0';
+	}
+	const exp = value.toExponential();
+	const [base, exponent] = exp.split('e');
+	const floatLength = base.split('.')[1]?.length || 0;
+	const finalizedExp = `${base.replace('.', '')}e${parseInt(exponent) - floatLength}`;
+	const stringifiedValue = String(value).replace('+', '');
+	return finalizedExp.length < stringifiedValue.length ? finalizedExp : stringifiedValue;
 }
diff --git a/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/amd/dep2.js b/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/amd/dep2.js
@@ -4,7 +4,7 @@ define(['exports'], (function (exports) { 'use strict';
 
 	console.log('This is the output when a missing export is reexported');
 
-	var _missingExportShim$1 = void 0;
+	var _missingExportShim$1 = undefined;
 
 	console.log(_missingExportShim$1);
 

diff --git a/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/cjs/dep2.js b/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/cjs/dep2.js
@@ -4,7 +4,7 @@ var _missingExportShim = void 0;
 
 console.log('This is the output when a missing export is reexported');
 
-var _missingExportShim$1 = void 0;
+var _missingExportShim$1 = undefined;
 
 console.log(_missingExportShim$1);
 

diff --git a/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/es/dep2.js b/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/es/dep2.js
@@ -2,7 +2,7 @@ var _missingExportShim = void 0;
 
 console.log('This is the output when a missing export is reexported');
 
-var _missingExportShim$1 = void 0;
+var _missingExportShim$1 = undefined;
 
 console.log(_missingExportShim$1);
 

diff --git a/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/system/dep2.js b/test/chunking-form/samples/missing-export-reused-deconflicting/_expected/system/dep2.js
@@ -7,7 +7,7 @@ System.register([], (function (exports) {
 
 			console.log('This is the output when a missing export is reexported');
 
-			var _missingExportShim$1 = exports("previousShimmedExport", void 0);
+			var _missingExportShim$1 = exports("previousShimmedExport", undefined);
 
 			console.log(_missingExportShim$1);
 

diff --git a/test/form/samples/supports-core-js/_expected.js b/test/form/samples/supports-core-js/_expected.js
@@ -9133,7 +9133,7 @@ function requireEs_number_minSafeInteger () {
 	// `Number.MIN_SAFE_INTEGER` constant
 	// https://tc39.es/ecma262/#sec-number.min_safe_integer
 	$({ target: 'Number', stat: true, nonConfigurable: true, nonWritable: true }, {
-	  MIN_SAFE_INTEGER: -0x1FFFFFFFFFFFFF
+	  MIN_SAFE_INTEGER: -9007199254740991
 	});
 	return es_number_minSafeInteger;
 }
@@ -9265,7 +9265,7 @@ function requireEs_number_toExponential () {
 	var stringSlice = uncurryThis(''.slice);
 
 	// Edge 17-
-	var ROUNDS_PROPERLY = nativeToExponential(-6.9e-11, 4) === '-6.9000e-11'
+	var ROUNDS_PROPERLY = nativeToExponential(-69e-12, 4) === '-6.9000e-11'
 	  // IE11- && Edge 14-
 	  && nativeToExponential(1.255, 2) === '1.25e+0'
 	  // FF86-, V8 ~ Chrome 49-50

diff --git a/test/form/samples/supports-es5-shim/_expected.js b/test/form/samples/supports-es5-shim/_expected.js
@@ -180,7 +180,7 @@ function requireEs5Shim () {
 		            var n = +num;
 		            if (isActualNaN(n)) {
 		                n = 0;
-		            } else if (n !== 0 && n !== (1 / 0) && n !== -(1 / 0)) {
+		            } else if (n !== 0 && n !== (1 / 0) && n !== -Infinity) {
 		                n = (n > 0 || -1) * floor(abs(n));
 		            }
 		            return n;
@@ -1384,7 +1384,7 @@ function requireEs5Shim () {
 		    // string format defined in 15.9.1.15. All fields are present in the String.
 		    // The time zone is always UTC, denoted by the suffix Z. If the time value of
 		    // this object is not a finite Number a RangeError exception is thrown.
-		    var negativeDate = -62198755200000;
+		    var negativeDate = -621987552e5;
 		    var negativeYearString = '-000001';
 		    var hasNegativeDateBug = Date.prototype.toISOString && new Date(negativeDate).toISOString().indexOf(negativeYearString) === -1; // eslint-disable-line max-len
 		    var hasSafari51DateBug = Date.prototype.toISOString && new Date(-1).toISOString() !== '1969-12-31T23:59:59.999Z';
@@ -1642,7 +1642,7 @@ function requireEs5Shim () {
 		                        if (isLocalTime) {
 		                            result = toUTC(result);
 		                        }
-		                        if (-8.64e15 <= result && result <= 8.64e15) {
+		                        if (-864e13 <= result && result <= 8.64e15) {
 		                            return result;
 		                        }
 		                    }
@@ -2043,7 +2043,7 @@ function requireEs5Shim () {
 		                            match[0].replace(separator2, function () {
 		                                for (var i = 1; i < arguments.length - 2; i++) {
 		                                    if (typeof arguments[i] === 'undefined') {
-		                                        match[i] = void 0;
+		                                        match[i] = undefined;
 		                                    }
 		                                }
 		                            });
@@ -2080,7 +2080,7 @@ function requireEs5Shim () {
 		    // then the output array is truncated so that it contains no more than limit
 		    // elements.
 		    // "0".split(undefined, 0) -> []
-		    } else if ('0'.split(void 0, 0).length) {
+		    } else if ('0'.split(undefined, 0).length) {
 		        StringPrototype.split = function split(separator, limit) {
 		            if (typeof separator === 'undefined' && limit === 0) {
 		                return [];