unified: Add test with chain of accessors

Author: asgerf

unified/ql/test/library-tests/dataflow/accessors_local.swift

@@ -72,3 +72,15 @@ func t9() {
     y = source("t9.1")
     closure()
 }
+
+func t10() {
+    var y: String = "safe"
+    var x1: String { y }
+    var x2: String { x1 }
+    var x3: String { x2 }
+    let closure = {
+        sink(x3)  // $ hasValueFlow=t9.1
+    }
+    y = source("t9.1")
+    closure()
+}

unified/ql/test/library-tests/dataflow/test.expected

@@ -45,6 +45,9 @@ edges
 | accessors_local.swift:72:5:72:5 | y | accessors_local.swift:73:5:73:11 | closure [y] | provenance |  |
 | accessors_local.swift:72:9:72:22 | source(...) | accessors_local.swift:72:5:72:5 | y | provenance |  |
 | accessors_local.swift:73:5:73:11 | closure [y] | accessors_local.swift:70:14:70:14 | x | provenance |  |
+| accessors_local.swift:84:5:84:5 | y | accessors_local.swift:85:5:85:11 | closure [y] | provenance |  |
+| accessors_local.swift:84:9:84:22 | source(...) | accessors_local.swift:84:5:84:5 | y | provenance |  |
+| accessors_local.swift:85:5:85:11 | closure [y] | accessors_local.swift:82:14:82:15 | x3 | provenance |  |
 | accessors_static.swift:8:32:8:45 | source(...) | accessors_static.swift:10:10:10:12 | ... .x | provenance |  |
 | accessors_static.swift:18:19:18:32 | source(...) | accessors_static.swift:21:10:21:12 | ... .x | provenance |  |
 | accessors_static.swift:27:19:27:32 | source(...) | accessors_static.swift:31:10:31:12 | ... .x | provenance |  |
@@ -579,6 +582,10 @@ nodes
 | accessors_local.swift:72:5:72:5 | y | semmle.label | y |
 | accessors_local.swift:72:9:72:22 | source(...) | semmle.label | source(...) |
 | accessors_local.swift:73:5:73:11 | closure [y] | semmle.label | closure [y] |
+| accessors_local.swift:82:14:82:15 | x3 | semmle.label | x3 |
+| accessors_local.swift:84:5:84:5 | y | semmle.label | y |
+| accessors_local.swift:84:9:84:22 | source(...) | semmle.label | source(...) |
+| accessors_local.swift:85:5:85:11 | closure [y] | semmle.label | closure [y] |
 | accessors_static.swift:8:32:8:45 | source(...) | semmle.label | source(...) |
 | accessors_static.swift:10:10:10:12 | ... .x | semmle.label | ... .x |
 | accessors_static.swift:18:19:18:32 | source(...) | semmle.label | source(...) |
@@ -1197,6 +1204,7 @@ testFailures
 | accessors_local.swift:55:10:55:10 | x | accessors_local.swift:54:9:54:22 | source(...) | accessors_local.swift:55:10:55:10 | x | $@ | accessors_local.swift:54:9:54:22 | source(...) | source(...) |
 | accessors_local.swift:61:14:61:14 | x | accessors_local.swift:59:21:59:34 | source(...) | accessors_local.swift:61:14:61:14 | x | $@ | accessors_local.swift:59:21:59:34 | source(...) | source(...) |
 | accessors_local.swift:70:14:70:14 | x | accessors_local.swift:72:9:72:22 | source(...) | accessors_local.swift:70:14:70:14 | x | $@ | accessors_local.swift:72:9:72:22 | source(...) | source(...) |
+| accessors_local.swift:82:14:82:15 | x3 | accessors_local.swift:84:9:84:22 | source(...) | accessors_local.swift:82:14:82:15 | x3 | $@ | accessors_local.swift:84:9:84:22 | source(...) | source(...) |
 | accessors_static.swift:10:10:10:12 | ... .x | accessors_static.swift:8:32:8:45 | source(...) | accessors_static.swift:10:10:10:12 | ... .x | $@ | accessors_static.swift:8:32:8:45 | source(...) | source(...) |
 | accessors_static.swift:21:10:21:12 | ... .x | accessors_static.swift:18:19:18:32 | source(...) | accessors_static.swift:21:10:21:12 | ... .x | $@ | accessors_static.swift:18:19:18:32 | source(...) | source(...) |
 | accessors_static.swift:31:10:31:12 | ... .x | accessors_static.swift:27:19:27:32 | source(...) | accessors_static.swift:31:10:31:12 | ... .x | $@ | accessors_static.swift:27:19:27:32 | source(...) | source(...) |