fix: dead control flow with deep nested if (#19403)

lib/javascript/JavascriptParser.js

@@ -2200,6 +2200,9 @@ class JavascriptParser extends Parser {
 			this.inExecutedPath(false, () => {
 				this.walkExpression(statement.test);
 				this.walkNestedStatement(statement.consequent);
+			});
+
+			this.inExecutedPath(true, () => {
 				if (statement.alternate) {
 					this.walkNestedStatement(statement.alternate);
 				}

test/__snapshots__/StatsTestCases.basictest.js.snap

@@ -4781,22 +4781,15 @@ exports[`StatsTestCases should print correct stats for track-returned 1`] = `
 ./used8.js X bytes [built] [code generated]
 ./used9.js X bytes [built] [code generated]
 ./used16.js X bytes [built] [code generated]
+./used69.js X bytes [built] [code generated]
 ./used17.js X bytes [built] [code generated]
 ./used18.js X bytes [built] [code generated]
 ./used19.js X bytes [built] [code generated]
 ./used48.js X bytes [built] [code generated]
 ./used35.js X bytes [built] [code generated]
 ./used10.js X bytes [built] [code generated]
-./used11.js X bytes [built] [code generated]
-+ 38 modules
-
-WARNING in ./index.js 227:3-20
-Module not found: Error: Can't resolve 'fail47' in 'Xdir/track-returned'
-
-1 warning has detailed information that is not shown.
-Use 'stats.errorDetails: true' resp. '--stats-error-details' to show it.
-
-webpack x.x.x compiled with 1 warning in X ms"
++ 56 modules
+webpack x.x.x compiled successfully in X ms"
 `;
 
 exports[`StatsTestCases should print correct stats for tree-shaking 1`] = `

test/statsCases/track-returned/index.js

@@ -224,7 +224,8 @@ it("should work correct for try catch and loops", () => {
 				require('./used16');
 			}
 
-			require('fail47');
+			// TODO potential improvement
+			require('./used69');
 		} catch (e) {
 			require('./used17');
 		} finally {
@@ -565,7 +566,7 @@ it("should work correct for try catch and loops", () => {
 		}
 	}
 
-	function test25() {
+	function test25a() {
 		try {
 			return;
 		} finally {
@@ -703,6 +704,16 @@ it("should work correct for try catch and loops", () => {
 		require("./used51");
 	}
 
+	function test36() {
+		test();
+
+		throw 1;
+
+		function test() {
+			require("./used67")
+		}
+	}
+
 	for(let i = 0; i < 1; i++)
 		if (rand())
 			require('./used1');
@@ -778,6 +789,410 @@ it("should work correct for if #4", () => {
 	}
 });
 
+it("should work correct for if #5", () => {
+	if (rand())
+		return;
+	else if (rand())
+		return;
+	else {
+		const test = 1;
+		require("./used52")
+	}
+});
+
+it("should work correct for if #6", () => {
+	if (rand())
+		return;
+	else {
+		const test = 1;
+		require("./used53")
+	}
+});
+
+it("should work correct for if #7", () => {
+	if (rand())
+		return;
+	else
+		return;
+
+	require("fail");
+});
+
+it("should work correct for if #8", () => {
+	if (rand()) {
+		rand()
+	} else if (rand()) {
+		rand()
+	} else
+		return;
+
+	require("fail");
+});
+
+it("should work correct for if #9", () => {
+	if (true) {
+		return;
+	} else if (rand()) {
+		require("fail");
+	} else
+		require("fail");
+
+	require("fail");
+});
+
+it("should work correct for if #10", () => {
+	if (rand()) {
+		return;
+	} else if (true) {
+		return;
+	} else
+		require("fail");
+
+	require("fail");
+});
+
+it("should work correct for if #11", () => {
+	if (false)
+		return;
+	else if (rand()) {
+		return;
+	} else
+		return;
+
+	require("fail");
+});
+
+it("should work correct for if #12", () => {
+	if (false)
+		return;
+	else if (false) {
+		return;
+	} else
+		return;
+
+	require("fail");
+});
+
+it("should work correct for if #13", () => {
+	if (true)
+		return;
+	else if (true) {
+		return;
+	} else
+		return;
+
+	require("fail");
+});
+
+it("should work correct for if #13", () => {
+	if (false)
+		return;
+	else if (false) {
+		return;
+	} else {}
+
+	require("./used54");
+});
+
+it("should work correct for if #14", () => {
+	if (fn())
+		return;
+	else if (fn()) {
+		fn()
+		require("./used55");
+	}
+
+	require("./used56");
+});
+
+it("should work correct for if #15", () => {
+	if (true) {
+		return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #16", () => {
+	if (true) return;
+
+	const test = 1;
+	require("fail");
+});
+
+it("should work correct for if #17", () => {
+	if (false) return;
+
+	const test = 1;
+	require("./used57");
+});
+
+it("should work correct for if #18", () => {
+	if (rand()) return;
+
+	const test = 1;
+	require("./used58");
+});
+
+it("should work correct for if #19", () => {
+	if (!rand())
+		// if reference flag is false ,then show the form and update the model with relative type list
+		return rand();
+	else {
+		if (rand()) {
+			rand();
+			require("./used59")
+			rand();
+		} else {
+			rand();
+			require("./used60");
+			rand();
+		}
+	}
+
+	require("./used61");
+});
+
+it("should work correct for if #20", () => {
+	if (rand()) {
+		return;
+	} else if (rand()) {
+		return;
+	} else if (rand()) {
+		return;
+	} else if (rand()) {
+		return;
+	}
+
+	require("./used62");
+});
+
+it("should work correct for if #21", () => {
+	if (rand())
+		return;
+	else if (rand())
+		return;
+	else if (rand())
+		return;
+	else if (rand())
+		return;
+
+	require("./used63");
+});
+
+it("should work correct for if #22", () => {
+	if (rand()) {
+		if (true) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+
+		require("fail");
+	} else {
+		return;
+		require("fail");
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #23", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (true) {
+			return;
+		} else {
+			return;
+		}
+
+		require("fail");
+	} else {
+		return;
+		require("fail");
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #24", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+	}
+
+	require("./used64");
+});
+
+it("should work correct for if #25", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+	} else if (rand()) {
+		return;
+	}
+
+	require("./used65");
+});
+
+it("should work correct for if #26", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+	} else if (rand()) {
+		return;
+	} else if (rand()) {}
+
+	require("./used66");
+});
+
+it("should work correct for if #22", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else if (rand()) {
+			return;
+		} else {
+			return;
+		}
+
+		// require("fail");
+	} else if (rand()) {
+		if (rand()) {
+			return;
+		} else {
+			return;
+		}
+
+		// require("fail");
+	} else {
+		return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #23", () => {
+	if (rand()) {
+		if (rand())
+			return;
+		else if (rand())
+			return;
+		else
+			return;
+
+		require("fail");
+	} else if (rand()) {
+		if (rand())
+			return;
+		else
+			return;
+
+		require("fail");
+	} else {
+		return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #24", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else {
+			return;
+		}
+	} else {
+		return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #25", () => {
+	if (rand())
+		return;
+	else
+		if (rand())
+			return;
+		else
+			return;
+
+	require("fail");
+});
+
+it("should work correct for if #26", () => {
+	if (rand()) {
+		return;
+	} else
+		if (rand())
+			return;
+		else
+			return;
+
+	require("fail");
+});
+
+it("should work correct for if #27", () => {
+	if (rand())
+		return;
+	else {
+		if (rand())
+			return;
+		else
+			return;
+	}
+
+	require("fail");
+});
+
+it("should work correct for if #28", () => {
+	if (rand()) {
+		if (rand()) {
+			return;
+		} else {
+			const test = 1;
+			require("./used68")
+			return;
+		}
+
+		require("fail");
+	}
+});
+
+it("should work correct for if #29", () => {
+	if (rand()) {
+		return;
+		if (rand()) {
+			return;
+		} else {
+			return;
+		}
+
+		require("fail");
+	}
+});
+
+
 it("should not include unused assets", (done) => {
 	let a, b;
 	(function() {

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

@@ -1,5 +1,5 @@
 module.exports = {
 	validate(stats) {
-		expect(stats.compilation.modules.size).toBe(52);
+		expect(stats.compilation.modules.size).toBe(70);
 	}
 };

test/statsCases/track-returned/used52.js

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

test/statsCases/track-returned/used53.js

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

test/statsCases/track-returned/used54.js

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

test/statsCases/track-returned/used55.js

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

test/statsCases/track-returned/used56.js

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

test/statsCases/track-returned/used57.js

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

test/statsCases/track-returned/used58.js

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

test/statsCases/track-returned/used59.js

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

test/statsCases/track-returned/used60.js

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

test/statsCases/track-returned/used61.js

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

test/statsCases/track-returned/used62.js

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

test/statsCases/track-returned/used63.js

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

test/statsCases/track-returned/used64.js

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

test/statsCases/track-returned/used65.js

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

test/statsCases/track-returned/used66.js

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

test/statsCases/track-returned/used67.js

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

test/statsCases/track-returned/used68.js

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

test/statsCases/track-returned/used69.js

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