fix: terminated state for `if/else` (#19404)

lib/javascript/JavascriptParser.js

@@ -2197,16 +2197,22 @@ class JavascriptParser extends Parser {
 	walkIfStatement(statement) {
 		const result = this.hooks.statementIf.call(statement);
 		if (result === undefined) {
-			this.inExecutedPath(false, () => {
-				this.walkExpression(statement.test);
-				this.walkNestedStatement(statement.consequent);
-			});
+			this.walkExpression(statement.test);
+			this.walkNestedStatement(statement.consequent);
 
-			this.inExecutedPath(true, () => {
-				if (statement.alternate) {
-					this.walkNestedStatement(statement.alternate);
-				}
-			});
+			const consequentTerminated = this.scope.terminated;
+			this.scope.terminated = undefined;
+
+			if (statement.alternate) {
+				this.walkNestedStatement(statement.alternate);
+			}
+
+			const alternateTerminated = this.scope.terminated;
+
+			this.scope.terminated =
+				consequentTerminated && alternateTerminated
+					? this.scope.terminated
+					: undefined;
 		} else {
 			this.inExecutedPath(true, () => {
 				if (result) {

test/__snapshots__/StatsTestCases.basictest.js.snap

@@ -4788,7 +4788,7 @@ exports[`StatsTestCases should print correct stats for track-returned 1`] = `
 ./used48.js X bytes [built] [code generated]
 ./used35.js X bytes [built] [code generated]
 ./used10.js X bytes [built] [code generated]
-+ 56 modules
++ 65 modules
 webpack x.x.x compiled successfully in X ms"
 `;
 

test/statsCases/track-returned/index.js

@@ -306,7 +306,7 @@ it("should work correct for try catch and loops", () => {
 			require("./used15")
 		}
 
-		// require("fail35");
+		require("fail35");
 	}
 
 	function test7() {
@@ -826,7 +826,7 @@ it("should work correct for if #8", () => {
 	} else
 		return;
 
-	require("fail");
+	require("./used70");
 });
 
 it("should work correct for if #9", () => {
@@ -1082,7 +1082,7 @@ it("should work correct for if #22", () => {
 			return;
 		}
 
-		// require("fail");
+		require("fail");
 	} else {
 		return;
 	}
@@ -1192,6 +1192,139 @@ it("should work correct for if #29", () => {
 	}
 });
 
+it("should work correct for if #30", () => {
+	if (rand()) {
+		rand();
+		return;
+	} else {
+		rand();
+	}
+
+	require("./used71")
+});
+
+it("should work correct for if #31", () => {
+	if (rand()) {
+		rand();
+	} else {
+		rand();
+		return;
+	}
+
+	require("./used72")
+});
+
+it("should work correct for if #32", () => {
+	if (rand()) {
+		rand();
+		return;
+	} else {
+		rand();
+		return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #33", () => {
+	if (rand()) {
+		rand();
+		return;
+	} else if (rand()) {
+		rand()
+	} else {
+		rand();
+		return;
+	}
+
+	require("./used73");
+});
+
+it("should work correct for if #34", () => {
+	if (rand()) {
+		rand();
+		return;
+	} else if (rand()) {
+		rand();
+		return;
+	} else {
+		rand();
+	}
+
+	require("./used74");
+});
+
+it("should work correct for if #35", () => {
+	if (rand()) {
+		rand();
+	} else if (rand()) {
+		rand();
+		return;
+	} else {
+		rand();
+		return;
+	}
+
+	require("./used75");
+});
+
+it("should work correct for if #36", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+		require("fail");
+	} else if (rand()) {
+		rand();
+	} else {
+		rand();
+	}
+
+	require("./used76");
+});
+
+it("should work correct for if #37", () => {
+	if (rand()) {
+		rand();
+	} else if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+		require("fail");
+	} else {
+		rand();
+	}
+
+	require("./used77");
+});
+
+it("should work correct for if #38", () => {
+	if (rand()) {
+		rand();
+	} else if (rand()) {
+		rand();
+	} else {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+		require("fail");
+	}
+
+	require("./used78");
+});
+
 
 it("should not include unused assets", (done) => {
 	let a, b;

test/statsCases/track-returned/test.config.js

@@ -1,5 +1,5 @@
 module.exports = {
 	validate(stats) {
-		expect(stats.compilation.modules.size).toBe(70);
+		expect(stats.compilation.modules.size).toBe(79);
 	}
 };

test/statsCases/track-returned/used70.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used71.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used72.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used73.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used74.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used75.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used76.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used77.js

@@ -0,0 +1 @@
+module.exports = 10;

test/statsCases/track-returned/used78.js

@@ -0,0 +1 @@
+module.exports = 10;