Expand test for Extract Tuple Instruction

Author: owen-mc

go/ql/test/library-tests/semmle/go/IR/test.expected

@@ -1,6 +1,6 @@
-| test.go:9:2:9:16 | ... := ...[0] | file://:0:0:0:0 | bool |
-| test.go:9:2:9:16 | ... := ...[1] | file://:0:0:0:0 | bool |
-| test.go:15:2:15:20 | ... := ...[0] | file://:0:0:0:0 | string |
-| test.go:15:2:15:20 | ... := ...[1] | file://:0:0:0:0 | bool |
-| test.go:21:2:21:22 | ... := ...[0] | file://:0:0:0:0 | string |
-| test.go:21:2:21:22 | ... := ...[1] | file://:0:0:0:0 | bool |
+| test.go:9:2:9:16 | ... := ...[0] | test.go:9:13:9:16 | <-... | 0 | file://:0:0:0:0 | bool |
+| test.go:9:2:9:16 | ... := ...[1] | test.go:9:13:9:16 | <-... | 1 | file://:0:0:0:0 | bool |
+| test.go:15:2:15:20 | ... := ...[0] | test.go:15:13:15:20 | index expression | 0 | file://:0:0:0:0 | string |
+| test.go:15:2:15:20 | ... := ...[1] | test.go:15:13:15:20 | index expression | 1 | file://:0:0:0:0 | bool |
+| test.go:21:2:21:22 | ... := ...[0] | test.go:21:13:21:22 | type assertion | 0 | file://:0:0:0:0 | string |
+| test.go:21:2:21:22 | ... := ...[1] | test.go:21:13:21:22 | type assertion | 1 | file://:0:0:0:0 | bool |

go/ql/test/library-tests/semmle/go/IR/test.ql

@@ -1,4 +1,5 @@
 import go
 
-from IR::ExtractTupleElementInstruction extract
-select extract, extract.getResultType()
+from IR::ExtractTupleElementInstruction extract, IR::Instruction base, int idx, Type resultType
+where extract.extractsElement(base, idx) and resultType = extract.getResultType()
+select extract, base, idx, resultType