Fix contextual typing for post-spread tuple elements (#52769)

tests/cases/compiler/spreadsAndContextualTupleTypes.ts

@@ -0,0 +1,43 @@
+// @strict: true
+// @noEmit: true
+
+declare function fx1<T extends [string, string, string, 'a' | 'b']>(x: T): T;
+declare function fx2<T extends [...string[], 'a' | 'b']>(x: T): T;
+
+const t3 = ['x', 'y', 'z'] as const;
+
+fx1(['x', 'y', 'z', 'a']);
+fx1([...t3, 'a']);
+
+fx2(['x', 'y', 'z', 'a']);
+fx2([...t3, 'a']);
+
+const x1: [...string[], '!'] = ['!'];
+const x2: [...string[], '!'] = ['a', '!'];
+const x3: [...string[], '!'] = [...t3, '!'];
+
+// Repro from #52684
+
+const staticPath1Level = ["home"] as const;
+const staticPath2Level = ["home", "user"] as const;
+const staticPath3Level = ["home", "user", "downloads"] as const;
+
+const randomID = 'id' as string;
+
+declare function foo<const T>(path: T): T;
+
+const a1 = foo([...staticPath1Level, randomID, 'doc.pdf']);
+const a2 = foo([...staticPath2Level, randomID, 'doc.pdf']);
+const a3 = foo([...staticPath3Level, randomID, 'doc.pdf']);
+
+const b1 = foo([...staticPath1Level, randomID, 'folder', 'doc.pdf']);
+const b2 = foo([...staticPath2Level, randomID, 'folder', 'doc.pdf']);
+const b3 = foo([...staticPath3Level, randomID, 'folder', 'doc.pdf']);
+
+const c1 = foo([...staticPath1Level, randomID, 'folder', 'subfolder', 'doc.pdf']);
+const c2 = foo([...staticPath2Level, randomID, 'folder', 'subfolder', 'doc.pdf']);
+const c3 = foo([...staticPath3Level, randomID, 'folder', 'subfolder', 'doc.pdf']);
+
+const d1 = foo([...staticPath1Level, randomID, 'folder', 'subfolder', 'another-subfolder', 'doc.pdf']);
+const d2 = foo([...staticPath2Level, randomID, 'folder', 'subfolder', 'another-subfolder', 'doc.pdf']);
+const d3 = foo([...staticPath3Level, randomID, 'folder', 'subfolder', 'another-subfolder', 'doc.pdf']);