writeShellApplication: Expand test suite

pkgs/build-support/trivial-builders/test/writeShellApplication.nix

@@ -1,29 +1,141 @@
-/*
-  Run with:
-
-      cd nixpkgs
-      nix-build -A tests.trivial-builders.writeShellApplication
-*/
-
-{ lib, writeShellApplication, runCommand }:
+# Run with:
+# nix-build -A tests.trivial-builders.writeShellApplication
+{ writeShellApplication
+, writeTextFile
+, runCommand
+, lib
+, linkFarm
+, diffutils
+, hello
+}:
 let
-  pkg = writeShellApplication {
-    name = "test-script";
+  checkShellApplication = args@{name, expected, ...}:
+    let
+      writeShellApplicationArgs = builtins.removeAttrs args ["expected"];
+      script = writeShellApplication writeShellApplicationArgs;
+      executable = lib.getExe script;
+      expected' = writeTextFile {
+        name = "${name}-expected";
+        text = expected;
+      };
+      actual = "${name}-actual";
+    in
+    runCommand name { } ''
+      echo "Running test executable ${name}"
+      ${executable} > ${actual}
+      echo "Got output from test executable:"
+      cat ${actual}
+      echo "Checking test output against expected output:"
+      ${diffutils}/bin/diff --color --unified ${expected'} ${actual}
+      touch $out
+    '';
+in
+linkFarm "writeShellApplication-tests" {
+  test-meta =
+    let
+      script = writeShellApplication {
+        name = "test-meta";
+        text = "";
+        meta.description = "A test for the `writeShellApplication` `meta` argument.";
+      };
+    in
+    assert script.meta.mainProgram == "test-meta";
+    assert script.meta.description == "A test for the `writeShellApplication` `meta` argument.";
+    script;
+
+  test-runtime-inputs =
+    checkShellApplication {
+      name = "test-runtime-inputs";
+      text = ''
+        hello
+      '';
+      runtimeInputs = [ hello ];
+      expected = "Hello, world!\n";
+    };
+
+  test-runtime-env =
+    checkShellApplication {
+      name = "test-runtime-env";
+      runtimeEnv = {
+        MY_COOL_ENV_VAR = "my-cool-env-value";
+        MY_OTHER_COOL_ENV_VAR = "my-other-cool-env-value";
+        # Check that we can serialize a bunch of different types:
+        BOOL = true;
+        INT = 1;
+        LIST = [1 2 3];
+        MAP = {
+          a = "a";
+          b = "b";
+        };
+      };
+      text = ''
+        echo "$MY_COOL_ENV_VAR"
+        echo "$MY_OTHER_COOL_ENV_VAR"
+      '';
+      expected = ''
+        my-cool-env-value
+        my-other-cool-env-value
+      '';
+    };
+
+  test-check-phase =
+    checkShellApplication {
+      name = "test-check-phase";
+      text = "";
+      checkPhase = ''
+        echo "echo -n hello" > $target
+      '';
+      expected = "hello";
+    };
+
+  test-argument-forwarding =
+    checkShellApplication {
+      name = "test-argument-forwarding";
+      text = "";
+      derivationArgs.MY_BUILD_TIME_VARIABLE = "puppy";
+      derivationArgs.postCheck = ''
+        if [[ "$MY_BUILD_TIME_VARIABLE" != puppy ]]; then
+          echo "\$MY_BUILD_TIME_VARIABLE is not set to 'puppy'!"
+          exit 1
+        fi
+      '';
+      meta.description = "A test checking that `writeShellApplication` forwards extra arguments to `stdenv.mkDerivation`.";
+      expected = "";
+    };
+
+  test-exclude-shell-checks = writeShellApplication {
+    name = "test-exclude-shell-checks";
     excludeShellChecks = [ "SC2016" ];
     text = ''
-      echo -e '#!/usr/bin/env bash\n' \
-       'echo "$SHELL"' > /tmp/something.sh  # this line would normally
-                                            # ...cause shellcheck error
+      # Triggers SC2016: Expressions don't expand in single quotes, use double
+      # quotes for that.
+      echo '$SHELL'
     '';
   };
-in
-  assert pkg.meta.mainProgram == "test-script";
-  runCommand "test-writeShellApplication" { } ''
 
-    echo Testing if writeShellApplication builds without shellcheck error...
+  test-bash-options-pipefail = checkShellApplication {
+    name = "test-bash-options-pipefail";
+    text = ''
+      touch my-test-file
+      echo puppy | grep doggy | sed 's/doggy/puppy/g'
+      #            ^^^^^^^^^^ This will fail.
+      true
+    '';
+    # Don't use `pipefail`:
+    bashOptions = ["errexit" "nounset"];
+    expected = "";
+  };
 
-    target=${lib.getExe pkg}
-
-    touch $out
-  ''
+  test-bash-options-nounset = checkShellApplication {
+    name = "test-bash-options-nounset";
+    text = ''
+      echo -n "$someUndefinedVariable"
+    '';
+    # Don't use `nounset`:
+    bashOptions = [];
+    # Don't warn about the undefined variable at build time:
+    excludeShellChecks = [ "SC2154" ];
+    expected = "";
+  };
 
+}