unikernel/duniverse/ppxlib/test/501_migrations/normal_migrations.t

@@ -0,0 +1,146 @@
+The 501 parsetree contains a parsing modificacion.
+[compare_on.exe <file>] checks if there's a diff between the
+AST's resulting from
+1. parsing <file> on 5.1.0 directly
+2. parsing <file> on 5.1.0, migrating down to 5.0.0 and migrating back to 5.1.0
+
+------------------
+
+Tests for the Parsetree change for type constraints in value bindings
+
+  $ echo "let x : int = 5" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let (x) : int = 5" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let _ : int = 5" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let f : type a b c. a -> b -> c = fun x y -> assert false" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let f = (fun (type a) (type b) (type c) -> (fun x y -> assert false : a -> b -> c))" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let _ = (fun (type a) (type b) (type c) -> (fun x y -> assert false : a -> b -> c))" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let f : type a . a -> a = fun x -> x" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let (x, y) : (int * int) = assert false" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let f : type a . a = assert false" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo 'let x : [`A] :> [`A | `B] = `A' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo 'let x : [`A | `B] = (`A : [`A] :> [`A | `B])' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo 'let x : <m:int; n:int> :> <m:int> = object method m = 0 method n = 1 end' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo 'let x :> <m:int> = object method m = 0 method n = 1 end' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+
+There used to be a problem in the upward migration to 5.1.0: the 5.1.0 parser parses the constraint as a pattern constraint.
+However, the upward migration makes a value binding constraint out of it. Since the internal AST was bumped to 5.2.0, this is no longer an issue.
+  $ echo "let ((x,y) : (int*int)) = (assert false: int * int)" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ echo "let f: type a. a option -> _ = assert false" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+
+Here we may expect a diff (downwards migrating should yield the same as in the example right above).
+However, those case are recoverable.
+
+First, both
+
+  $ echo "let f : 'a . 'a = (fun (type a) -> (assert false : a))" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+and
+  $ echo "let f : type a . a = assert false" > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+are translated to the same 5.0 AST tree. But the locations on the expression
+constraint and pattern constraint are only the same in the second case.
+Thus, we can distinguish between the two.
+
+Similarly, the syntactic translation for
+
+  $ echo 'let x :> [`A | `B] = `A' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+and
+
+  $ echo 'let x : [`A | `B] = (`A :> [ `A | `B ] )' > file.ml
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+are pretty close: The former is translated to "let (x: ø .  [`A | `B]) = (`A :> [`A | `B])"
+whereas the latter is mapped to "let (x: ø .  [`A | `B]) = ((`A :> [`A | `B]): [`A | `B]) ".
+However, the two case can be distingued by the fact that we have either an outward coercion
+or an outward constraint associated to a `Ptyp_poly([],...)` pattern constraint.
+
+Let's make sure that in the examples with diffs,
+the location invariants are still fulfilled.
+  $ echo "let ((x,y) : (int*int)) = (assert false: int * int)" > file.ml
+  $ ./identity_driver.exe -check -locations-check file.ml > /dev/null
+
+------------------
+
+Tests for the Parsetree change for generative functor applications
+
+
+  $ cat > file.ml << EOF
+  > module F () = struct end
+  > module M = F ()
+  > EOF
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ cat > file.ml << EOF
+  > module F () = struct end
+  > module M = F [@attr1] () [@attr2]
+  > EOF
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ cat > file.ml << EOF
+  > module F () = struct end
+  > module M = F(struct end)
+  > EOF
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]
+
+  $ cat > file.ml << EOF
+  > module F (N : sig end) = struct end
+  > module M = F (struct end)
+  > EOF
+  $ ./compare_on.exe file.ml ./identity_driver.exe | grep -v "without_migrations" | grep -v "with_migrations"
+  [1]