Generate the lockfile on the fly when entering the shell

Avoids the need for an explicit `nix run .#regenerate-lockfile`
nickel-lang · Jun 21, 2024 · a415c2e · a415c2e
1 parent 1b4c9ca
commit a415c2e
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Showing 5 changed files with 35 additions and 33 deletions.
diff --git a/lib/files.ncl b/lib/files.ncl
@@ -45,7 +45,6 @@ let NormaliseTargets = fun label files =>
 in
 let regenerate_files | Files -> nix.derivation.Derivation = fun files_to_generate =>
     let regnerate_one | String -> File -> nix.derivation.NixString = fun key file_descr =>
-        let file_content = file_descr.content in
         let target = file_descr.target in
         let copy_command =
           match {
@@ -54,11 +53,6 @@ let regenerate_files | Files -> nix.derivation.Derivation = fun files_to_generat
           }
             file_descr.materialisation_method
         in
-        let file_in_store =
-          nix.builtins.to_file
-            (nix.utils.escape_drv_name key)
-            file_content
-        in
         nix-s%"
             rm -f %{target}
             echo "Regenerating %{target}"
@@ -67,7 +61,7 @@ let regenerate_files | Files -> nix.derivation.Derivation = fun files_to_generat
             # XXX: If `source.file` is set explicitely to a relative path
             # and `materialisation_method` is `'Symlink`, this will link to the
             # original file, not one in the store. Not sure that's what we want.
-            %{copy_command} %{file_in_store} %{target}
+            %{copy_command} %{file_descr.file} %{target}
           "%
       in
     {

diff --git a/lib/lib.nix b/lib/lib.nix
@@ -169,23 +169,19 @@
       passAsFile = ["expectedLockfileContents"];
     } (
       if needNewLockfile
-      then
-        lib.warn ''
-          Lockfile contents are outdated. Please run "nix run .#regenerate-lockfile" to update them.
-        ''
-        ''
-          cp -r "${sources}" sources
-          if [ -f sources/nickel.lock.ncl ]; then
-            chmod +w sources sources/nickel.lock.ncl
-          else
-            chmod +w sources
-          fi
-          cp $expectedLockfileContentsPath sources/nickel.lock.ncl
-          cat > eval.ncl <<EOF
-          ${nickelWithImports "sources"}
-          EOF
-          ${nickel}/bin/nickel export eval.ncl --field config.flake > $out
-        ''
+      then ''
+        cp -r "${sources}" sources
+        if [ -f sources/nickel.lock.ncl ]; then
+          chmod +w sources sources/nickel.lock.ncl
+        else
+          chmod +w sources
+        fi
+        cp $expectedLockfileContentsPath sources/nickel.lock.ncl
+        cat > eval.ncl <<EOF
+        ${nickelWithImports "sources"}
+        EOF
+        ${nickel}/bin/nickel export eval.ncl --field config.flake > $out
+      ''
       else ''
         cat > eval.ncl <<EOF
         ${nickelWithImports sources}
@@ -212,9 +208,14 @@
     nickelResult = callNickel {
       inherit nickelFile baseDir flakeInputs lockFileContents;
     };
+    enrichedFlakeInputs =
+      flakeInputs
+      // {
+        "%%organist_internal".nickelLock = builtins.toFile "nickel.lock.ncl" (buildLockFileContents lockFileContents);
+      };
   in
     {rawNickel = nickelResult;}
-    // (importFromNickel flakeInputs system baseDir (builtins.fromJSON
+    // (importFromNickel enrichedFlakeInputs system baseDir (builtins.fromJSON
         (builtins.unsafeDiscardStringContext (builtins.readFile nickelResult))));
 in {
   inherit

diff --git a/lib/lockfile.ncl b/lib/lockfile.ncl
@@ -0,0 +1,8 @@
+let filegen = import "files.ncl" in
+let nix = import "nix-interop/nix.ncl" in
+{
+  Schema = filegen.Schema,
+  config | Schema = {
+      files."nickel.lock.ncl".file = nix.import_nix "%%organist_internal#nickelLock",
+    }
+}
diff --git a/lib/schema.ncl b/lib/schema.ncl
@@ -1,5 +1,6 @@
 let nix = import "./nix-interop/nix.ncl" in
 let filegen = import "files.ncl" in
+let lockfile = import "lockfile.ncl" in
 {
   OrganistShells = {
     dev
@@ -70,4 +71,5 @@ let filegen = import "files.ncl" in
         },
     }
     & filegen
+    & lockfile
 }
diff --git a/run-test.sh b/run-test.sh
@@ -51,28 +51,24 @@ test_one_template () (
   sed -i "s/shells\.Bash/shells.$target/" project.ncl
   prepare_shell
 
-  STORED_LOCKFILE_CONTENTS="$(cat nickel.lock.ncl)"
   TEST_SCRIPT="$(nickel export --format raw <<<'(import "'"$PROJECT_ROOT"'/lib/shell-tests.ncl").'"$target"'.script')"
 
   echo "Running with incorrect nickel.lock.ncl" 1>&2
+  echo '{}' > nickel.lock.ncl
   nix develop --accept-flake-config --print-build-logs --command bash <<<"$TEST_SCRIPT"
 
   if [[ $isFull == false ]]; then
     return
   fi
 
   echo "Running without nickel.lock.ncl" 1>&2
-  rm nickel.lock.ncl
+  rm -f nickel.lock.ncl
   nix develop --accept-flake-config --print-build-logs --command bash <<<"$TEST_SCRIPT"
 
   echo "Run with proper nickel.lock.ncl" 1>&2
-  nix run .\#regenerate-lockfile
-  PROPER_LOCKFILE_CONTENTS="$(cat nickel.lock.ncl)"
   nix develop --accept-flake-config --print-build-logs --command bash <<<"$TEST_SCRIPT"
 
   echo "Testing without flakes" 1>&2
-  # restore lockfile
-  cat > nickel.lock.ncl <<<"$STORED_LOCKFILE_CONTENTS"
   # pretend it's not flake anymore
   rm flake.*
   cat > shell.nix <<EOF
@@ -86,14 +82,15 @@ in
 EOF
 
   echo "Running with incorrect nickel.lock.ncl" 1>&2
+  rm -f nickel.lock.ncl
+  echo '{}' > nickel.lock.ncl
   nix develop --impure -f shell.nix -I nixpkgs="$NIXPKGS_PATH" --command bash <<<"$TEST_SCRIPT"
 
   echo "Running without nickel.lock.ncl" 1>&2
-  rm nickel.lock.ncl
+  rm -f nickel.lock.ncl
   nix develop --impure -f shell.nix -I nixpkgs="$NIXPKGS_PATH" --command bash <<<"$TEST_SCRIPT"
 
   echo "Run with proper nickel.lock.ncl" 1>&2
-  cat > nickel.lock.ncl <<<"$PROPER_LOCKFILE_CONTENTS"
   nix develop --impure -f shell.nix -I nixpkgs="$NIXPKGS_PATH" --command bash <<<"$TEST_SCRIPT"
 
   popd