ci: introduce 'drone-skip-pipeline' plugin

expectations:
  * speed-up
  * resource preservation (don't needlessly run (full) builds when
    nothing pertinent changed)

caveat: this does not (just yet) work with Gitea (a rewrite underway)

[skip ci]

.drone.starlark

@@ -7,11 +7,39 @@ def main(ctx):
 			"kind": "pipeline",
 			"type": "docker",
 			"name": "golangci-lint",
+			"clone": {"disable": True},
+			"environment": {
+				"GOPROXY": "direct"
+			},
 			"steps": [
+				{
+					"name": "skip-check",
+					"image": "docker.io/immawanderer/drone-skip-pipeline:linux-amd64",
+					"pull": "always",
+					"settings": {
+						"rules": [
+							"*.go",
+							"*.sum",
+							"*.mod",
+							".golangci.yml"
+						]
+					},
+				},
+				{
+					"name": "clone",
+					"image": "docker.io/alpine/git",
+					"pull": "always",
+					"depends_on": ["skip-check"],
+					"commands": [
+						"git clone ${DRONE_GIT_HTTP_URL} .",
+						"git checkout ${DRONE_COMMIT}"
+					]
+				},
 				{
 					"name": "golangci-lint",
 					"image": "docker.io/immawanderer/archlinux-go-fyne:linux-amd64",
 					"pull": "always",
+					"depends_on": ["clone"],
 					"commands": [
 						"curl -sSfL " +
 						"https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh"+
@@ -30,6 +58,9 @@ def main(ctx):
 			"node": {
 				"r": "w"
 			},
+			"environment": {
+				"GOPROXY": "direct"
+			},
 			"steps": [
 				{
 					"name": "pull nix",
@@ -276,6 +307,9 @@ def main(ctx):
 			"node": {
 				"r": "w"
 			},
+			"environment": {
+				"GOPROXY": "direct"
+			},
 			"steps": [
 				{
 					"name": "pull archlinux",
@@ -353,6 +387,9 @@ def main(ctx):
 			"node": {
 				"r": "w"
 			},
+			"environment": {
+				"GOPROXY": "direct"
+			},
 			"steps": [
 				{
 					"name": "pull fedora",

.golangci.yml

@@ -34,8 +34,10 @@ linters:
     - ineffassign
     # - ifshort
     - misspell
-    # - prealloc #  disable for now as it might be premature optimisation
+    - prealloc
     - revive
+    - rowserrcheck
+    - sqlclosecheck
     - unconvert
     - unparam
     - varcheck

.pre-commit-config.yaml

@@ -45,10 +45,13 @@ repos:
   - repo: https://github.com/dnephin/pre-commit-golang
     rev: v0.5.0
     hooks:
-      - id: go-mod-tidy
+      - id: go-vet
       - id: go-unit-tests
+      - id: go-cyclo
+        args: [-over=15]
       - id: golangci-lint
       - id: go-build
+      - id: go-mod-tidy
   - repo: local
     hooks:
       - id: nix-build

flake.lock

@@ -16,21 +16,6 @@
         "type": "github"
       }
     },
-    "nix-filter": {
-      "locked": {
-        "lastModified": 1653590866,
-        "narHash": "sha256-E4yKIrt/S//WfW5D9IhQ1dVuaAy8RE7EiCMfnbrOC78=",
-        "owner": "numtide",
-        "repo": "nix-filter",
-        "rev": "3e81a637cdf9f6e9b39aeb4d6e6394d1ad158e16",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "nix-filter",
-        "type": "github"
-      }
-    },
     "nixgl": {
       "inputs": {
         "nixpkgs": [
@@ -70,7 +55,6 @@
     "root": {
       "inputs": {
         "flake-compat": "flake-compat",
-        "nix-filter": "nix-filter",
         "nixgl": "nixgl",
         "nixpkgs": "nixpkgs"
       }

flake.nix

@@ -10,17 +10,11 @@
       flake = false;
       inputs.nixpkgs.follows = "nixpkgs";
     };
-    nix-filter = {
-      url = "github:numtide/nix-filter";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
   };
 
-  outputs = { self, nixgl, nix-filter, nixpkgs, ... }:
+  outputs = { self, nixgl, nixpkgs, ... }:
     let
 
-      projname = "go-xkcdreader";
-
       # to work with older version of flakes
       lastModifiedDate =
         self.lastModifiedDate or self.lastModified or "19700101";
@@ -45,10 +39,6 @@
       });
     in
     rec {
-      formatter = forAllSystems (system:
-        nixpkgsFor.${system}.nixpkgs-fmt
-      );
-
       packages = forAllSystems (system:
         let
           pkgs = nixpkgsFor.${system};
@@ -56,7 +46,7 @@
         in
         rec {
           go-xkcdreader = with pkgs; buildGoModule rec {
-            pname = "${projname}";
+            pname = "go-xkcdreader";
             buildInputs = [
               gcc
               libglvnd # instead of libGL
@@ -77,7 +67,7 @@
             nativeBuildInputs = [ pkgconfig ];
 
             overrideModAttrs = _: {
-              # GOPROXY = "direct";
+              GOPROXY = "direct";
             };
 
             inherit version;
@@ -93,35 +83,15 @@
 
             modSha256 = lib.fakeSha256;
             # dont't forget to update vendorSha256 whenever go.mod or go.sum change
-            vendorSha256 = "sha256-LvdcTbj8cFlaIBsq1VLfLF2Tu9HiZzGO8igD766nMLE=";
+            vendorSha256 = "sha256-gaIoacCs0PcvmFW8dQOFUb9KU1u6KUiFmGQ/ERcVwjc=";
 
             # In 'nix develop', we don't need a copy of the source tree
             # in the Nix store.
-            src = nix-filter.lib.filter {
+            src = lib.cleanSource ./.;
-              root = lib.cleanSource ./.;
-              exclude = [
-                ./flake.nix
-                ./flake.lock
-                ./default.nix
-                ./shell.nix
-
-                ./check-fmt
-                ./README.md
-                ./LICENSE
-
-                ./.drone.starlark
-                ./.envrc
-                ./.example.vimrc
-                ./.gitattributes
-                ./.gitignore
-                ./.golangci.yml
-                ./.pre-commit-config.yaml
-              ];
-            };
 
             meta = {
               description = "an offline-capable xkcd webcomic reader written in Go";
-              homepage = "https://git.dotya.ml/wanderer/${projname}";
+              homepage = "https://git.dotya.ml/wanderer/go-xkcdreader";
               license = lib.licenses.gpl3;
               maintainers = [ "wanderer" ];
               platforms = lib.platforms.linux ++ lib.platforms.darwin;
@@ -135,7 +105,7 @@
         go-xkcdreader = {
           type = "app";
           program =
-            "${self.packages.${system}.${projname}}/bin/${projname}";
+            "${self.packages.${system}.go-xkcdreader}/bin/go-xkcdreader";
         };
         default = go-xkcdreader;
       });
@@ -168,7 +138,7 @@
             nix-store --query --references $(nix-instantiate shell.nix) | \
               xargs nix-store --realise | \
               xargs nix-store --query --requisites | \
-              cachix push ${projname}
+              cachix push go-xkcdreader
           '';
           add-license = pkgs.writeShellScriptBin "add-license" ''
             go run github.com/google/addlicense@v1.0.0 -v \
@@ -179,7 +149,7 @@
         {
           default = with pkgs; mkShell
             {
-              name = "${projname}-" + version;
+              name = "go-xkcdreader-" + version;
 
               GOFLAGS = "-buildmode=pie -trimpath -mod=readonly -modcacherw";
               GOLDFLAGS = "-s -w -X cmd.version=${version}";