diff --git a/src/ast/nodes/ForStatement.ts b/src/ast/nodes/ForStatement.ts
index 6def8e46003..f07001e3716 100644
--- a/src/ast/nodes/ForStatement.ts
+++ b/src/ast/nodes/ForStatement.ts
@@ -42,7 +42,7 @@ export default class ForStatement extends StatementBase {
 		if (this.test) this.test.include(context, includeChildrenRecursively);
 		const { breakFlow } = context;
 		if (this.update) this.update.include(context, includeChildrenRecursively);
-		if (this.body) this.body.include(context, includeChildrenRecursively);
+		this.body.include(context, includeChildrenRecursively);
 		context.breakFlow = breakFlow;
 	}
 
diff --git a/src/ast/nodes/IfStatement.ts b/src/ast/nodes/IfStatement.ts
index f9e9b0daa2f..73b6bb944f6 100644
--- a/src/ast/nodes/IfStatement.ts
+++ b/src/ast/nodes/IfStatement.ts
@@ -19,16 +19,11 @@ export default class IfStatement extends StatementBase implements DeoptimizableE
 	test!: ExpressionNode;
 	type!: NodeType.tIfStatement;
 
-	private isTestValueAnalysed = false;
 	private testValue: LiteralValueOrUnknown;
 
 	bind() {
 		super.bind();
-		if (!this.isTestValueAnalysed) {
-			this.testValue = UnknownValue;
-			this.isTestValueAnalysed = true;
-			this.testValue = this.test.getLiteralValueAtPath(EMPTY_PATH, EMPTY_IMMUTABLE_TRACKER, this);
-		}
+		this.testValue = this.test.getLiteralValueAtPath(EMPTY_PATH, EMPTY_IMMUTABLE_TRACKER, this);
 	}
 
 	deoptimizeCache() {
diff --git a/src/ast/scopes/CatchScope.ts b/src/ast/scopes/CatchScope.ts
index 6bbaa797632..08e977006d8 100644
--- a/src/ast/scopes/CatchScope.ts
+++ b/src/ast/scopes/CatchScope.ts
@@ -8,7 +8,7 @@ export default class CatchScope extends ParameterScope {
 	addDeclaration(
 		identifier: Identifier,
 		context: AstContext,
-		init: ExpressionEntity | null = null,
+		init: ExpressionEntity | null,
 		isHoisted: boolean | 'function'
 	): LocalVariable {
 		if (isHoisted) {
diff --git a/src/ast/values.ts b/src/ast/values.ts
index df024efe881..3f563c5928d 100644
--- a/src/ast/values.ts
+++ b/src/ast/values.ts
@@ -47,6 +47,7 @@ export const UNKNOWN_EXPRESSION: ExpressionEntity = {
 	included: true,
 	toString: () => '[[UNKNOWN]]'
 };
+
 export const UNDEFINED_EXPRESSION: ExpressionEntity = {
 	deoptimizePath: () => {},
 	getLiteralValueAtPath: () => undefined,
@@ -59,6 +60,7 @@ export const UNDEFINED_EXPRESSION: ExpressionEntity = {
 	included: true,
 	toString: () => 'undefined'
 };
+
 const returnsUnknown: RawMemberDescription = {
 	value: {
 		callsArgs: null,
diff --git a/test/form/samples/binary-expressions/_config.js b/test/form/samples/binary-expressions/_config.js
new file mode 100644
index 00000000000..1c861eec011
--- /dev/null
+++ b/test/form/samples/binary-expressions/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'handles binary expression side-effects'
+};
diff --git a/test/form/samples/binary-expressions/_expected.js b/test/form/samples/binary-expressions/_expected.js
new file mode 100644
index 00000000000..5ff02006ea4
--- /dev/null
+++ b/test/form/samples/binary-expressions/_expected.js
@@ -0,0 +1,25 @@
+if ((1 + 1).unknown) {
+	console.log('retained');
+} else {
+	console.log('retained');
+}
+console.log('retained 1');
+console.log('retained 2');
+console.log('retained 3');
+console.log('retained 4');
+console.log('retained 5');
+console.log('retained 6');
+console.log('retained 7');
+console.log('retained 8');
+console.log('retained 9');
+console.log('retained 10');
+console.log('retained 11');
+console.log('retained 12');
+console.log('retained 13');
+console.log('retained 14');
+console.log('retained 15');
+console.log('retained 16');
+console.log('retained 17');
+if (1 in 2) console.log('retained 18');
+if (1 instanceof 2) console.log('retained 19');
+console.log('retained 20');
diff --git a/test/form/samples/binary-expressions/main.js b/test/form/samples/binary-expressions/main.js
new file mode 100644
index 00000000000..0263ffe9303
--- /dev/null
+++ b/test/form/samples/binary-expressions/main.js
@@ -0,0 +1,28 @@
+if ((1 + 1).unknown) {
+	console.log('retained');
+} else {
+	console.log('retained');
+}
+
+if (1 != '1') console.log('removed');
+if (1 !== 1) console.log('removed');
+if (4 % 2 === 0) console.log('retained 1');
+if ((6 & 3) === 2) console.log('retained 2');
+if (2 * 3 === 6) console.log('retained 3');
+if (2 ** 3 === 8) console.log('retained 4');
+if (2 + 3 === 5) console.log('retained 5');
+if (3 - 2 === 1) console.log('retained 6');
+if (6 / 3 === 2) console.log('retained 7');
+if (1 < 2 ) console.log('retained 8');
+if (3 << 1 === 6) console.log('retained 9');
+if (3 <= 4) console.log('retained 10');
+if (1 == '1') console.log('retained 11');
+if (1 === 1) console.log('retained 12');
+if (3 > 2) console.log('retained 13');
+if (3 >= 2) console.log('retained 14');
+if (6 >> 1 === 3) console.log('retained 15');
+if (-1 >>> 28 === 15) console.log('retained 16');
+if (3 ^ 5 === 6) console.log('retained 17');
+if (1 in 2) console.log('retained 18');
+if (1 instanceof 2) console.log('retained 19');
+if (2 | 4 === 6) console.log('retained 20');
diff --git a/test/form/samples/break-control-flow/break-statement-labels/_expected.js b/test/form/samples/break-control-flow/break-statement-labels/_expected.js
index 81784a01622..d7080a80bb6 100644
--- a/test/form/samples/break-control-flow/break-statement-labels/_expected.js
+++ b/test/form/samples/break-control-flow/break-statement-labels/_expected.js
@@ -31,11 +31,11 @@ outer: {
 	console.log('retained');
 }
 
-function withReturn() {
+function withConsequentReturn() {
 	outer: {
 		inner: {
-			if (globalThis.unknown) break inner;
-			else return;
+			if (globalThis.unknown) return;
+			else break inner;
 		}
 		console.log('retained');
 	}
@@ -46,4 +46,16 @@ function withReturn() {
 	}
 }
 
-withReturn();
+withConsequentReturn();
+
+function withAlternateReturn() {
+	outer: {
+		inner: {
+			if (globalThis.unknown) break inner;
+			else return;
+		}
+		console.log('retained');
+	}
+}
+
+withAlternateReturn();
diff --git a/test/form/samples/break-control-flow/break-statement-labels/main.js b/test/form/samples/break-control-flow/break-statement-labels/main.js
index 336ae3797ee..b7ac267b7f1 100644
--- a/test/form/samples/break-control-flow/break-statement-labels/main.js
+++ b/test/form/samples/break-control-flow/break-statement-labels/main.js
@@ -48,11 +48,11 @@ outer: {
 	console.log('retained');
 }
 
-function withReturn() {
+function withConsequentReturn() {
 	outer: {
 		inner: {
-			if (globalThis.unknown) break inner;
-			else return;
+			if (globalThis.unknown) return;
+			else break inner;
 			console.log('removed');
 		}
 		console.log('retained');
@@ -67,4 +67,17 @@ function withReturn() {
 	}
 }
 
-withReturn();
+withConsequentReturn();
+
+function withAlternateReturn() {
+	outer: {
+		inner: {
+			if (globalThis.unknown) break inner;
+			else return;
+			console.log('removed');
+		}
+		console.log('retained');
+	}
+}
+
+withAlternateReturn();
diff --git a/test/form/samples/builtin-prototypes/array-expression/_config.js b/test/form/samples/builtin-prototypes/array-expression/_config.js
index 90f3b19cd39..c18d1c7f176 100644
--- a/test/form/samples/builtin-prototypes/array-expression/_config.js
+++ b/test/form/samples/builtin-prototypes/array-expression/_config.js
@@ -1,4 +1,3 @@
 module.exports = {
-	description: 'Tree-shake known array prototype functions',
-	options: { output: { name: 'bundle' } }
+	description: 'Tree-shake known array prototype functions'
 };
diff --git a/test/form/samples/builtin-prototypes/array-expression/_expected.js b/test/form/samples/builtin-prototypes/array-expression/_expected.js
index effa27f383d..7318911baaa 100644
--- a/test/form/samples/builtin-prototypes/array-expression/_expected.js
+++ b/test/form/samples/builtin-prototypes/array-expression/_expected.js
@@ -3,6 +3,8 @@ const map4 = [ 1 ].map( x => x ).map( x => console.log( 1 ) );
 const map5 = [ 1 ].map( x => console.log( 1 ) ).map( x => x );
 const map7 = [ 1 ].map( x => x ).map( x => x ).map( x => console.log( 1 ) );
 const map8 = [ 1 ].map( x => x ).map( x => console.log( 1 ) ).map( x => x );
+
+[]();
 const _everyEffect = [ 1 ].every( () => console.log( 1 ) || true );
 const _filterEffect = [ 1 ].filter( () => console.log( 1 ) || true );
 const _findEffect = [ 1 ].find( () => console.log( 1 ) || true );
diff --git a/test/form/samples/builtin-prototypes/array-expression/main.js b/test/form/samples/builtin-prototypes/array-expression/main.js
index 7fa15d0881d..a04bdfa57e3 100644
--- a/test/form/samples/builtin-prototypes/array-expression/main.js
+++ b/test/form/samples/builtin-prototypes/array-expression/main.js
@@ -12,6 +12,8 @@ const map6 = [ 1 ].map( x => x ).map( x => x ).map( x => x );
 const map7 = [ 1 ].map( x => x ).map( x => x ).map( x => console.log( 1 ) );
 const map8 = [ 1 ].map( x => x ).map( x => console.log( 1 ) ).map( x => x );
 
+[]();
+
 // accessor methods
 const _includes = [].includes( 1 ).valueOf();
 const _indexOf = [].indexOf( 1 ).toPrecision( 1 );
diff --git a/test/form/samples/class-constructor-side-effect/_expected.js b/test/form/samples/class-constructor-side-effect/_expected.js
new file mode 100644
index 00000000000..469da25d52a
--- /dev/null
+++ b/test/form/samples/class-constructor-side-effect/_expected.js
@@ -0,0 +1,11 @@
+class Effect {
+	constructor () {
+		console.log( 'Foo' );
+	}
+}
+
+new Effect();
+
+class Empty {}
+
+new Empty.doesNotExist();
diff --git a/test/form/samples/class-constructor-side-effect/_expected/amd.js b/test/form/samples/class-constructor-side-effect/_expected/amd.js
deleted file mode 100644
index 1b939aa8b03..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/amd.js
+++ /dev/null
@@ -1,11 +0,0 @@
-define(function () { 'use strict';
-
-	class Foo {
-		constructor () {
-			console.log( 'Foo' );
-		}
-	}
-
-	new Foo;
-
-});
diff --git a/test/form/samples/class-constructor-side-effect/_expected/cjs.js b/test/form/samples/class-constructor-side-effect/_expected/cjs.js
deleted file mode 100644
index ad3db871b73..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/cjs.js
+++ /dev/null
@@ -1,9 +0,0 @@
-'use strict';
-
-class Foo {
-	constructor () {
-		console.log( 'Foo' );
-	}
-}
-
-new Foo;
diff --git a/test/form/samples/class-constructor-side-effect/_expected/es.js b/test/form/samples/class-constructor-side-effect/_expected/es.js
deleted file mode 100644
index 705e3506882..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/es.js
+++ /dev/null
@@ -1,7 +0,0 @@
-class Foo {
-	constructor () {
-		console.log( 'Foo' );
-	}
-}
-
-new Foo;
diff --git a/test/form/samples/class-constructor-side-effect/_expected/iife.js b/test/form/samples/class-constructor-side-effect/_expected/iife.js
deleted file mode 100644
index a047aa4e0d1..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/iife.js
+++ /dev/null
@@ -1,12 +0,0 @@
-(function () {
-	'use strict';
-
-	class Foo {
-		constructor () {
-			console.log( 'Foo' );
-		}
-	}
-
-	new Foo;
-
-}());
diff --git a/test/form/samples/class-constructor-side-effect/_expected/system.js b/test/form/samples/class-constructor-side-effect/_expected/system.js
deleted file mode 100644
index c50f93205ef..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/system.js
+++ /dev/null
@@ -1,16 +0,0 @@
-System.register([], function () {
-	'use strict';
-	return {
-		execute: function () {
-
-			class Foo {
-				constructor () {
-					console.log( 'Foo' );
-				}
-			}
-
-			new Foo;
-
-		}
-	};
-});
diff --git a/test/form/samples/class-constructor-side-effect/_expected/umd.js b/test/form/samples/class-constructor-side-effect/_expected/umd.js
deleted file mode 100644
index 82f801be7d2..00000000000
--- a/test/form/samples/class-constructor-side-effect/_expected/umd.js
+++ /dev/null
@@ -1,14 +0,0 @@
-(function (factory) {
-	typeof define === 'function' && define.amd ? define(factory) :
-	factory();
-}(function () { 'use strict';
-
-	class Foo {
-		constructor () {
-			console.log( 'Foo' );
-		}
-	}
-
-	new Foo;
-
-}));
diff --git a/test/form/samples/class-constructor-side-effect/main.js b/test/form/samples/class-constructor-side-effect/main.js
index 705e3506882..2704996853a 100644
--- a/test/form/samples/class-constructor-side-effect/main.js
+++ b/test/form/samples/class-constructor-side-effect/main.js
@@ -1,7 +1,18 @@
-class Foo {
+class Effect {
 	constructor () {
 		console.log( 'Foo' );
 	}
 }
 
-new Foo;
+new Effect();
+
+class NoEffect {
+	constructor () {
+	}
+}
+
+new NoEffect();
+
+class Empty {}
+
+new Empty.doesNotExist();
diff --git a/test/form/samples/side-effects-switch-statements/_expected.js b/test/form/samples/side-effects-switch-statements/_expected.js
index 1637398c2b5..6b541d9096e 100644
--- a/test/form/samples/side-effects-switch-statements/_expected.js
+++ b/test/form/samples/side-effects-switch-statements/_expected.js
@@ -30,3 +30,7 @@ switch ( globalThis.unknown ) {
 			effect();
 	}
 }());
+
+switch ( globalThis.unknown ) {
+	case effect():
+}
diff --git a/test/form/samples/side-effects-switch-statements/main.js b/test/form/samples/side-effects-switch-statements/main.js
index 306c82ecf5c..14763c4bd5b 100644
--- a/test/form/samples/side-effects-switch-statements/main.js
+++ b/test/form/samples/side-effects-switch-statements/main.js
@@ -44,3 +44,7 @@ switch ( globalThis.unknown ) {
 		default:
 	}
 }());
+
+switch ( globalThis.unknown ) {
+	case effect():
+}
diff --git a/test/form/samples/unary-expressions/_config.js b/test/form/samples/unary-expressions/_config.js
new file mode 100644
index 00000000000..9e363ae5176
--- /dev/null
+++ b/test/form/samples/unary-expressions/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'handles unary expression side-effects'
+};
diff --git a/test/form/samples/unary-expressions/_expected.js b/test/form/samples/unary-expressions/_expected.js
new file mode 100644
index 00000000000..d51c6bfe41b
--- /dev/null
+++ b/test/form/samples/unary-expressions/_expected.js
@@ -0,0 +1,13 @@
+if ((!true).unknown) {
+	console.log('retained');
+} else {
+	console.log('retained');
+}
+
+console.log('retained 1');
+console.log('retained 2');
+console.log('retained 3');
+if (delete 1) console.log('retained 4');
+console.log('retained 5');
+console.log('retained 6');
+console.log('retained 7');
diff --git a/test/form/samples/unary-expressions/main.js b/test/form/samples/unary-expressions/main.js
new file mode 100644
index 00000000000..c22c4ebd151
--- /dev/null
+++ b/test/form/samples/unary-expressions/main.js
@@ -0,0 +1,13 @@
+if ((!true).unknown) {
+	console.log('retained');
+} else {
+	console.log('retained');
+}
+
+if (!false) console.log('retained 1');
+if (+'1' === 1) console.log('retained 2');
+if (-1 + 2 === 1) console.log('retained 3');
+if (delete 1) console.log('retained 4');
+if (typeof 1 === 'number') console.log('retained 5');
+if (void 1 === undefined) console.log('retained 6');
+if (~1 === -2) console.log('retained 7');
diff --git a/test/form/samples/undefined-var/_expected.js b/test/form/samples/undefined-var/_expected.js
index e10c01c8cef..710306c2a45 100644
--- a/test/form/samples/undefined-var/_expected.js
+++ b/test/form/samples/undefined-var/_expected.js
@@ -1,8 +1,10 @@
 var z;
-console.log('no');
-console.log('no');
-if (z)
-	console.log('yes');
-if (!z)
-	console.log('no');
+
+console.log('retained');
+
+console.log('retained');
+
+if (z) console.log('retained');
+else console.log('retained');
+
 z = 1;
diff --git a/test/form/samples/undefined-var/main.js b/test/form/samples/undefined-var/main.js
index d6763907d01..7e219955ebe 100644
--- a/test/form/samples/undefined-var/main.js
+++ b/test/form/samples/undefined-var/main.js
@@ -1,16 +1,14 @@
 var x;
 var y = undefined;
 var z;
-if (x)
-	console.log('yes');
-if (!x)
-	console.log('no');
-if (y)
-	console.log('yes');
-if (!y)
-	console.log('no');
-if (z)
-	console.log('yes');
-if (!z)
-	console.log('no');
+
+if (x) console.log('removed');
+else console.log('retained');
+
+if (y) console.log('removed');
+else console.log('retained');
+
+if (z) console.log('retained');
+else console.log('retained');
+
 z = 1;