Merge pull request #368 from numtide/feat/ci-flag

CI flag

cli/cli.go

@@ -37,6 +37,8 @@ type Format struct {
 
 	CpuProfile string `optional:"" help:"The file into which a cpu profile will be written."`
 
+	Ci bool `help:"Runs treefmt in a CI mode, enabling --no-cache, --fail-on-change and adjusting some other settings best suited to a CI use case."`
+
 	formatters     map[string]*format.Formatter
 	globalExcludes []glob.Glob
 

cli/format.go

@@ -34,6 +34,37 @@ func (f *Format) Run() (err error) {
 	// set log level and other options
 	f.configureLogging()
 
+	// ci mode
+	if f.Ci {
+		f.NoCache = true
+		f.FailOnChange = true
+
+		// ensure INFO level
+		if f.Verbosity < 1 {
+			f.Verbosity = 1
+		}
+		// reconfigure logging
+		f.configureLogging()
+
+		log.Info("ci mode enabled")
+
+		startAfter := time.Now().
+			// truncate to second precision
+			Truncate(time.Second).
+			// add one second
+			Add(1 * time.Second).
+			// a little extra to ensure we don't start until the next second
+			Add(10 * time.Millisecond)
+
+		log.Debugf("waiting until %v before continuing", startAfter)
+
+		// Wait until we tick over into the next second before processing to ensure our EPOCH level modtime comparisons
+		// for change detection are accurate.
+		// This can fail in CI between checkout and running treefmt if everything happens too quickly.
+		// For humans, the second level precision should not be a problem as they are unlikely to run treefmt in sub-second succession.
+		<-time.After(time.Until(startAfter))
+	}
+
 	// cpu profiling
 	if f.CpuProfile != "" {
 		cpuProfile, err := os.Create(f.CpuProfile)

docs/usage.md

@@ -31,6 +31,7 @@ Flags:
                                      <debug|info|warn|error|fatal>.
       --stdin                        Format the context passed in via stdin.
       --cpu-profile=STRING           The file into which a cpu profile will be written.
+      --ci                           Runs treefmt in a CI mode, enabling --no-cache, --fail-on-change and adjusting some other settings best suited to a CI use case.
 ```
 
 ## Arguments
@@ -112,13 +113,22 @@ Format the context passed in via stdin.
 
 The file into which a cpu profile will be written.
 
+### `--ci`
+
+Runs treefmt in a CI mode which does the following:
+
+-   ensures `INFO` level logging at a minimum
+-   enables `--no-cache` and `--fail-on-change`
+-   introduces a small startup delay so we do not start processing until the second after the process started, thereby
+    ensuring the accuracy of our change detection based on second-level `modtime`.
+
 ### `-V, --version`
 
 Print version.
 
 ## CI integration
 
-Typically, you would use `treefmt` in CI with the `--fail-on-change` and `--no-cache flags`.
+Typically, you would use `treefmt` in CI with the `--ci` flag.
 
 You can configure a `treefmt` job in a GitHub pipeline for Ubuntu with `nix-shell` like this:
 
@@ -141,5 +151,5 @@ jobs:
                   name: nix-community
                   authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
             - name: treefmt
-              run: nix-shell -p treefmt --run "treefmt --fail-on-change --no-cache"
+              run: nix-shell -p treefmt --run "treefmt --ci"
 ```

flake.lock

@@ -75,12 +75,27 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_3"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "gomod2nix": {
       "inputs": {
-        "flake-utils": [
-          "devshell",
-          "flake-utils"
-        ],
+        "flake-utils": "flake-utils_2",
         "nixpkgs": [
           "nixpkgs"
         ]
@@ -171,6 +186,21 @@
         "type": "github"
       }
     },
+    "systems_3": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
     "treefmt-nix": {
       "inputs": {
         "nixpkgs": [
@@ -178,11 +208,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1719887753,
-        "narHash": "sha256-p0B2r98UtZzRDM5miGRafL4h7TwGRC4DII+XXHDHqek=",
+        "lastModified": 1722330636,
+        "narHash": "sha256-uru7JzOa33YlSRwf9sfXpJG+UAV+bnBEYMjrzKrQZFw=",
         "owner": "numtide",
         "repo": "treefmt-nix",
-        "rev": "bdb6355009562d8f9313d9460c0d3860f525bc6c",
+        "rev": "768acdb06968e53aa1ee8de207fd955335c754b7",
         "type": "github"
       },
       "original": {

flake.nix

@@ -18,7 +18,6 @@
     gomod2nix = {
       url = "github:nix-community/gomod2nix";
       inputs.nixpkgs.follows = "nixpkgs";
-      inputs.flake-utils.follows = "devshell/flake-utils";
     };
     flake-compat.url = "github:nix-community/flake-compat";
     nix-filter.url = "github:numtide/nix-filter";

nix/devshell.nix

@@ -30,6 +30,16 @@ perSystem.devshell.mkShell {
 
   commands = [
     {package = perSystem.gomod2nix.default;}
+    # This custom command is needed to prevent a conflict between --tree-root and --tree-root-file.
+    # treefmt-nix sets --tree-root-file whilst treefmt defaults --tree-root from $PRJ_ROOT, which is set by numtide/devshell.
+    {
+      name = "fmt";
+      help = "runs `nix fmt` but unsets $PRJ_ROOT first";
+      package = pkgs.writeShellScriptBin "fmt" ''
+        unset PRJ_ROOT
+        nix fmt -- "$@"
+      '';
+    }
     {
       name = "docs:dev";
       help = "serve docs for local development";

renovate.json

@@ -1,6 +1,4 @@
 {
-  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": [
-    "config:recommended"
-  ]
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "extends": ["config:recommended"]
 }