tests: simplify initialisation and wiring

pararameterisation is not actually needed the way things are currently
set up, and it confused me when trying to understand what the code does.

all but one test sources vars-and-functions.sh, which nominally only
defines variables, but in practice is always coupled with the actual
initialisation. while the cleaner way of making this more legible would
be to source variables and initialisation separately, this would produce
a huge diff.

doc/manual/src/contributing/testing.md

@@ -162,14 +162,14 @@ ran test tests/functional/${testName}.sh... [PASS]
 or without `make`:
 
 ```shell-session
-$ ./mk/run-test.sh tests/functional/${testName}.sh tests/functional/init.sh
+$ ./mk/run-test.sh tests/functional/${testName}.sh
 ran test tests/functional/${testName}.sh... [PASS]
 ```
 
 To see the complete output, one can also run:
 
 ```shell-session
-$ ./mk/debug-test.sh tests/functional/${testName}.sh tests/functional/init.sh
+$ ./mk/debug-test.sh tests/functional/${testName}.sh
 +(${testName}.sh:1) foo
 output from foo
 +(${testName}.sh:2) bar
@@ -204,7 +204,7 @@ edit it like so:
 Then, running the test with `./mk/debug-test.sh` will drop you into GDB once the script reaches that point:
 
 ```shell-session
-$ ./mk/debug-test.sh tests/functional/${testName}.sh tests/functional/init.sh
+$ ./mk/debug-test.sh tests/functional/${testName}.sh
 ...
 + gdb blash blub
 GNU gdb (GDB) 12.1

mk/debug-test.sh

@@ -3,12 +3,8 @@
 set -eu -o pipefail
 
 test=$1
-init=${2-}
 
 dir="$(dirname "${BASH_SOURCE[0]}")"
 source "$dir/common-test.sh"
 
-if [ -n "$init" ]; then
-    (run "$init" 2>/dev/null > /dev/null)
-fi
 run "$test"

mk/lib.mk

@@ -87,15 +87,14 @@ $(foreach script, $(bin-scripts), $(eval $(call install-program-in,$(script),$(b
 $(foreach script, $(bin-scripts), $(eval programs-list += $(script)))
 $(foreach script, $(noinst-scripts), $(eval programs-list += $(script)))
 $(foreach template, $(template-files), $(eval $(call instantiate-template,$(template))))
-install_test_init=tests/functional/init.sh
 $(foreach test, $(install-tests), \
-  $(eval $(call run-test,$(test),$(install_test_init))) \
+  $(eval $(call run-test,$(test))) \
   $(eval installcheck: $(test).test))
 $(foreach test-group, $(install-tests-groups), \
-  $(eval $(call run-test-group,$(test-group),$(install_test_init))) \
+  $(eval $(call run-test-group,$(test-group))) \
   $(eval installcheck: $(test-group).test-group) \
   $(foreach test, $($(test-group)-tests), \
-    $(eval $(call run-test,$(test),$(install_test_init))) \
+    $(eval $(call run-test,$(test))) \
     $(eval $(test-group).test-group: $(test).test)))
 
 # Compilation database.

mk/run-test.sh

@@ -8,7 +8,6 @@ yellow=""
 normal=""
 
 test=$1
-init=${2-}
 
 dir="$(dirname "${BASH_SOURCE[0]}")"
 source "$dir/common-test.sh"
@@ -22,9 +21,6 @@ if [ -t 1 ]; then
 fi
 
 run_test () {
-    if [ -n "$init" ]; then
-        (run "$init" 2>/dev/null > /dev/null)
-    fi
     log="$(run "$test" 2>&1)" && status=0 || status=$?
 }
 

mk/tests.mk

@@ -12,8 +12,8 @@ endef
 
 define run-test
 
-  $(eval $(call run-bash,$1.test,$1 $(test-deps),mk/run-test.sh $1 $2))
-  $(eval $(call run-bash,$1.test-debug,$1 $(test-deps),mk/debug-test.sh $1 $2))
+  $(eval $(call run-bash,$1.test,$1 $(test-deps),mk/run-test.sh $1))
+  $(eval $(call run-bash,$1.test-debug,$1 $(test-deps),mk/debug-test.sh $1))
 
 endef
 

tests/functional/init.sh → tests/functional/common/init.sh

@@ -1,6 +1,3 @@
-# Don't start the daemon
-source common/vars-and-functions.sh
-
 test -n "$TEST_ROOT"
 if test -d "$TEST_ROOT"; then
     chmod -R u+rw "$TEST_ROOT"
@@ -36,7 +33,7 @@ extra-experimental-features = flakes
 EOF
 
 # Initialise the database.
+# The flag itself does nothing, but running the command touches the store
 nix-store --init
-
-# Did anything happen?
+# Sanity check
 test -e "$NIX_STATE_DIR"/db/db.sqlite

tests/functional/common/vars-and-functions.sh.in

@@ -1,3 +1,5 @@
+# NOTE: instances of @variable@ are substituted as defined in /mk/templates.mk
+
 set -eu -o pipefail
 
 if [[ -z "${COMMON_VARS_AND_FUNCTIONS_SH_SOURCED-}" ]]; then
@@ -62,6 +64,8 @@ export IMPURE_VAR2=bar
 
 cacheDir=$TEST_ROOT/binary-cache
 
+source ./init.sh
+
 readLink() {
     ls -l "$1" | sed 's/.*->\ //'
 }

tests/functional/lang.sh

@@ -72,7 +72,7 @@ for i in lang/eval-fail-*.nix; do
         if [[ -e "lang/$i.flags" ]]; then
             sed -e 's/#.*//' < "lang/$i.flags"
         else
-            # note that show-trace is also set by init.sh
+            # note that show-trace is also set by common/init.sh
             echo "--eval --strict --show-trace"
         fi
     )"

tests/functional/local.mk

@@ -1,6 +1,5 @@
 nix_tests = \
   test-infra.sh \
-  init.sh \
   flakes/flakes.sh \
   flakes/develop.sh \
   flakes/run.sh \