Expanded test suite

* Lang now verifies errors and parse output

* Some new miscellaneous tests

* Easy way to update the tests

* Document workflow in manual

* Use `!` not `~` as separater char for sed

  It is confusing to use `~` when we are talking about paths and home
  directories!

* Test test suite itself (`test/lang-test/infra.sh`)

Additionally, run shellcheck on `tests/lang.sh` to help ensure it is
correct, now that is is more complex.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/lang/eval-fail-foldlStrict-strict-op-application.err.exp b/tests/lang/eval-fail-foldlStrict-strict-op-application.err.exp
new file mode 100644
index 000000000..0069285fb
--- /dev/null
+++ b/tests/lang/eval-fail-foldlStrict-strict-op-application.err.exp
@@ -0,0 +1,38 @@
+error:
+       … while calling the 'foldl'' builtin
+
+         at /pwd/lang/eval-fail-foldlStrict-strict-op-application.nix:2:1:
+
+            1| # Tests that the result of applying op is forced even if the value is never used
+            2| builtins.foldl'
+             | ^
+            3|   (_: f: f null)
+
+       … while calling anonymous lambda
+
+         at /pwd/lang/eval-fail-foldlStrict-strict-op-application.nix:3:7:
+
+            2| builtins.foldl'
+            3|   (_: f: f null)
+             |       ^
+            4|   null
+
+       … from call site
+
+         at /pwd/lang/eval-fail-foldlStrict-strict-op-application.nix:3:10:
+
+            2| builtins.foldl'
+            3|   (_: f: f null)
+             |          ^
+            4|   null
+
+       … while calling anonymous lambda
+
+         at /pwd/lang/eval-fail-foldlStrict-strict-op-application.nix:5:6:
+
+            4|   null
+            5|   [ (_: throw "Not the final value, but is still forced!") (_: 23) ]
+             |      ^
+            6|
+
+       error: Not the final value, but is still forced!