test: additional cases

tests/test-dirs/signature-help/sh-mix.t

@@ -0,0 +1,49 @@
+  $ cat >test.ml <<'EOF'
+  > let f x ~lbl_a y ~lbl_b z = ignore (x, lbl_a, lbl_b, z)
+  > let _ = f
+  > EOF
+
+First is the first parameter:
+  $ $MERLIN single signature-help -position 2:11 -filename test <test.ml |
+  > jq '.value.activeParameter'
+  0
+
+  $ cat >test.ml <<'EOF'
+  > let f x ~lbl_a y ~lbl_b z = ignore (x, lbl_a, lbl_b, z)
+  > let _ = f 0 
+  > EOF
+
+FIXME: After we expect the next non-labelled parameter to be active:
+  $ $MERLIN single signature-help -position 2:12 -filename test <test.ml |
+  > jq '.value.activeParameter'
+  0
+
+  $ cat >test.ml <<'EOF'
+  > let f x ~lbl_a y ~lbl_b z = ignore (x, lbl_a, lbl_b, z)
+  > let _ = f 0 3
+  > EOF
+
+It does happen when the expression is being writter:
+  $ $MERLIN single signature-help -position 2:12 -filename test <test.ml |
+  > jq '.value.activeParameter'
+  2
+
+  $ cat >test.ml <<'EOF'
+  > let f x ~lbl_a y ~lbl_b z = ignore (x, lbl_a, lbl_b, z)
+  > let _ = f 0 ~
+  > EOF
+
+And when a tilde is used the first labelled arg is higlighted:
+  $ $MERLIN single signature-help -position 2:13 -filename test <test.ml |
+  > jq '.value.activeParameter'
+  1
+
+  $ cat >test.ml <<'EOF'
+  > let f x ~lbl_a y ~lbl_b z = ignore (x, lbl_a, lbl_b, z)
+  > let _ = f 0 ~lbl_b
+  > EOF
+
+Or the second one is the name corresponds:
+  $ $MERLIN single signature-help -position 2:18 -filename test <test.ml |
+  > jq '.value.activeParameter'
+  3