Add try priors as finally lock label andecedents rather than pre finally label antecedents (#29790) (#29887)

Author: weswigham

src/compiler/binder.ts

@@ -1120,11 +1120,15 @@ namespace ts {
                 // We add the nodes within the `try` block to the `finally`'s antecedents if there's no catch block
                 // (If there is a `catch` block, it will have all these antecedents instead, and the `finally` will
                 // have the end of the `try` block and the end of the `catch` block)
+                let preFinallyPrior = preTryFlow;
                 if (!node.catchClause) {
                     if (tryPriors.length) {
+                        const preFinallyFlow = createBranchLabel();
+                        addAntecedent(preFinallyFlow, preTryFlow);
                         for (const p of tryPriors) {
-                            addAntecedent(preFinallyLabel, p);
+                            addAntecedent(preFinallyFlow, p);
                         }
+                        preFinallyPrior = finishFlowLabel(preFinallyFlow);
                     }
                 }
 
@@ -1156,7 +1160,7 @@ namespace ts {
                 //
                 // extra edges that we inject allows to control this behavior
                 // if when walking the flow we step on post-finally edge - we can mark matching pre-finally edge as locked so it will be skipped.
-                const preFinallyFlow: PreFinallyFlow = { flags: FlowFlags.PreFinally, antecedent: preTryFlow, lock: {} };
+                const preFinallyFlow: PreFinallyFlow = { flags: FlowFlags.PreFinally, antecedent: preFinallyPrior, lock: {} };
                 addAntecedent(preFinallyLabel, preFinallyFlow);
 
                 currentFlow = finishFlowLabel(preFinallyLabel);

tests/baselines/reference/controlFlowFinallyNoCatchAssignments.js

@@ -0,0 +1,33 @@
+//// [controlFlowFinallyNoCatchAssignments.ts]
+let x: number;
+x = Math.random();
+let a: number;
+try {
+    if (x) {
+        a = 1;
+    } else {
+        a = 2;
+    }
+} finally {
+    console.log(x);
+}
+
+console.log(a); // <- error here
+
+//// [controlFlowFinallyNoCatchAssignments.js]
+"use strict";
+var x;
+x = Math.random();
+var a;
+try {
+    if (x) {
+        a = 1;
+    }
+    else {
+        a = 2;
+    }
+}
+finally {
+    console.log(x);
+}
+console.log(a); // <- error here

tests/baselines/reference/controlFlowFinallyNoCatchAssignments.symbols

@@ -0,0 +1,38 @@
+=== tests/cases/compiler/controlFlowFinallyNoCatchAssignments.ts ===
+let x: number;
+>x : Symbol(x, Decl(controlFlowFinallyNoCatchAssignments.ts, 0, 3))
+
+x = Math.random();
+>x : Symbol(x, Decl(controlFlowFinallyNoCatchAssignments.ts, 0, 3))
+>Math.random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+>Math : Symbol(Math, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+
+let a: number;
+>a : Symbol(a, Decl(controlFlowFinallyNoCatchAssignments.ts, 2, 3))
+
+try {
+    if (x) {
+>x : Symbol(x, Decl(controlFlowFinallyNoCatchAssignments.ts, 0, 3))
+
+        a = 1;
+>a : Symbol(a, Decl(controlFlowFinallyNoCatchAssignments.ts, 2, 3))
+
+    } else {
+        a = 2;
+>a : Symbol(a, Decl(controlFlowFinallyNoCatchAssignments.ts, 2, 3))
+    }
+} finally {
+    console.log(x);
+>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
+>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>x : Symbol(x, Decl(controlFlowFinallyNoCatchAssignments.ts, 0, 3))
+}
+
+console.log(a); // <- error here
+>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
+>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>a : Symbol(a, Decl(controlFlowFinallyNoCatchAssignments.ts, 2, 3))
+

tests/baselines/reference/controlFlowFinallyNoCatchAssignments.types

@@ -0,0 +1,46 @@
+=== tests/cases/compiler/controlFlowFinallyNoCatchAssignments.ts ===
+let x: number;
+>x : number
+
+x = Math.random();
+>x = Math.random() : number
+>x : number
+>Math.random() : number
+>Math.random : () => number
+>Math : Math
+>random : () => number
+
+let a: number;
+>a : number
+
+try {
+    if (x) {
+>x : number
+
+        a = 1;
+>a = 1 : 1
+>a : number
+>1 : 1
+
+    } else {
+        a = 2;
+>a = 2 : 2
+>a : number
+>2 : 2
+    }
+} finally {
+    console.log(x);
+>console.log(x) : void
+>console.log : (message?: any, ...optionalParams: any[]) => void
+>console : Console
+>log : (message?: any, ...optionalParams: any[]) => void
+>x : number
+}
+
+console.log(a); // <- error here
+>console.log(a) : void
+>console.log : (message?: any, ...optionalParams: any[]) => void
+>console : Console
+>log : (message?: any, ...optionalParams: any[]) => void
+>a : number
+

tests/cases/compiler/controlFlowFinallyNoCatchAssignments.ts

@@ -0,0 +1,15 @@
+// @strict: true
+let x: number;
+x = Math.random();
+let a: number;
+try {
+    if (x) {
+        a = 1;
+    } else {
+        a = 2;
+    }
+} finally {
+    console.log(x);
+}
+
+console.log(a); // <- error here