tests: add a smoke test

nix-build tests -A smoke runs 19 scenarios in a single VM test: each
source type, each kind of target, flakes drawing inputs both ways, the
sentinel, prune, the checks of source names and target paths, and
writeDeploy.  That's quick enough to run after every change, while the
complete tests stay what a change has to pass in the end.  nix-build
tests doesn't build it, because the complete tests run the same
scenarios.

1 files changed, 45 insertions, 2 deletions

diff --git a/tests/default.nix b/tests/default.nix
index 686b130..f7ffa71 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -4,8 +4,11 @@
 # Build all with nix-build tests, or one with, e.g., nix-build tests -A flake.
 # The exhaustive tests add the combinations of options that no code path
 # tells apart from the ones the others cover; build them with nix-build tests
-# -A exhaustive, or one with, e.g., nix-build tests -A exhaustive.flake.  jq runs populate's jq programs for flakes
-# without VMs.
+# -A exhaustive, or one with, e.g., nix-build tests -A exhaustive.flake.
+# The smoke test runs a few scenarios covering each source type and each kind
+# of target in a single VM test, for checking changes quickly; build it with
+# nix-build tests -A smoke.  jq runs populate's jq programs for flakes without
+# VMs.
 { pkgs ? import ../pkgs {} }:
 
 let
@@ -46,8 +49,48 @@ let
       (builtins.mapAttrs
         (_: builtins.filter (scenario: scenario.exhaustive == exhaustive))
         scenarios));
+
+  # Names of the scenarios of the smoke test.
+  smokeNames = [
+    "file-local-checksum0-deleteExcluded0-filters0-inputsnone"
+    "file-sudo-checksum0-deleteExcluded0-filters1-inputsnone"
+    "git-remote-cleanExclude0-fetchAlways0-inputsnone-shallow0"
+    "git-local-shallow1-refs"
+    "symlink-local-absolute0-inputs0"
+    "pass-remote-storepass"
+    "passage-sudo-agedefault-dirstore"
+    "pipe-local"
+    "derivation-remote"
+    "flake-local-fetchOnTarget0-inputsrewrite-kindgit-materialize0"
+    "flake-sudo-fetchOnTarget1-inputsnone-kindgit-materialize0"
+    "flake-input-dep-remote-fetchOnTarget0-inputsgenerated-materialize0"
+    "flake-input-sub-local-fetchOnTarget0-materialize0"
+    "state-sentinel-local"
+    "prune-remote"
+    "names-local"
+    "paths-local"
+    "deploy-local-buildTarget0-etcFlake0-flakefile"
+    "deploy-sudo-allocateTTY"
+  ];
+  smokeScenarios = let
+    all = pkgs.lib.concatLists (builtins.attrValues scenarios);
+    selected = builtins.filter (scenario: builtins.elem scenario.name smokeNames) all;
+    missing = pkgs.lib.subtractLists (map (scenario: scenario.name) selected) smokeNames;
+  in
+    if missing != [] then
+      throw "tests: smoke test names missing scenarios: ${toString missing}"
+    else
+      selected;
 in
   testsOf false ""
+  # Not built by nix-build tests either, which runs these scenarios anyway.
+  // {
+    smoke.smoke = import ./vm.nix {
+      inherit pkgs gitHead;
+      name = "smoke";
+      scenarios = smokeScenarios;
+    };
+  }
   # An attribute set without recurseForDerivations, so nix-build tests
   # doesn't build them.
   // { exhaustive = testsOf true "exhaustive-"; }