Add failing tests first

core_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestGetCurrentVersion(t *testing.T) {
+func TestGetCurrentVersionForFlakeNix(t *testing.T) {
 	cwd, err := os.Getwd()
 	if err != nil {
 		t.Fatalf("failed to get current working directory: %v", err)
@@ -16,7 +16,34 @@ func TestGetCurrentVersion(t *testing.T) {
 			t.Fatalf("failed to rollback working directory: %v", err)
 		}
 	})
-	err = os.Chdir("testdata")
+	err = os.Chdir("testdata/flake")
+	if err != nil {
+		t.Fatalf("failed to walk through testdata directory: %v", err)
+	}
+
+	got, err := GetCurrentVersion("flake.nix")
+	if err != nil {
+		t.Fatalf("Getting the version has been failed: %s", err.Error())
+	}
+	want := "e57b65abbbf7a2d5786acc86fdf56cde060ed026"
+
+	if got != want {
+		t.Errorf("got %q, wanted %q", got, want)
+	}
+}
+
+func TestGetCurrentVersionForDefaultNix(t *testing.T) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("failed to get current working directory: %v", err)
+	}
+	t.Cleanup(func() {
+		err := os.Chdir(cwd)
+		if err != nil {
+			t.Fatalf("failed to rollback working directory: %v", err)
+		}
+	})
+	err = os.Chdir("testdata/classic")
 	if err != nil {
 		t.Fatalf("failed to walk through testdata directory: %v", err)
 	}
@@ -32,6 +59,28 @@ func TestGetCurrentVersion(t *testing.T) {
 	}
 }
 
+func TestGetCurrentVersionInEmptyDir(t *testing.T) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("failed to get current working directory: %v", err)
+	}
+	t.Cleanup(func() {
+		err := os.Chdir(cwd)
+		if err != nil {
+			t.Fatalf("failed to rollback working directory: %v", err)
+		}
+	})
+	err = os.Chdir("testdata/nothing")
+	if err != nil {
+		t.Fatalf("failed to walk through testdata directory: %v", err)
+	}
+
+	_, err = GetCurrentVersion("default.nix")
+	if !os.IsNotExist(err) {
+		t.Errorf("returned unexpected error: %v", err)
+	}
+}
+
 // Calling actual GitHub API, May be necessary to stub or disabling in CI
 func TestGetLastVersion(t *testing.T) {
 	got, err := GetLastVersion()
@@ -45,7 +94,7 @@ func TestGetLastVersion(t *testing.T) {
 	}
 }
 
-func TestTargetPath(t *testing.T) {
+func TestClassicTargetPath(t *testing.T) {
 	cwd, err := os.Getwd()
 	if err != nil {
 		t.Fatalf("failed to get current working directory: %v", err)
@@ -56,7 +105,7 @@ func TestTargetPath(t *testing.T) {
 			t.Fatalf("failed to rollback working directory: %v", err)
 		}
 	})
-	err = os.Chdir("testdata")
+	err = os.Chdir("testdata/classic")
 	if err != nil {
 		t.Fatalf("failed to walk through testdata directory: %v", err)
 	}
@@ -71,3 +120,30 @@ func TestTargetPath(t *testing.T) {
 		t.Errorf("got %q, wanted %q", got, want)
 	}
 }
+
+func TestTargetPathMultipleCandidates(t *testing.T) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("failed to get current working directory: %v", err)
+	}
+	t.Cleanup(func() {
+		err := os.Chdir(cwd)
+		if err != nil {
+			t.Fatalf("failed to rollback working directory: %v", err)
+		}
+	})
+	err = os.Chdir("testdata/classic/candidates")
+	if err != nil {
+		t.Fatalf("failed to walk through testdata directory: %v", err)
+	}
+
+	got, err := GetTargetPath()
+	if err != nil {
+		t.Fatalf("Failed to get target files: %s", err.Error())
+	}
+	want := "flake.nix"
+
+	if got != want {
+		t.Errorf("got %q, wanted %q", got, want)
+	}
+}

testdata/candidates/flake.nix

@@ -0,0 +1,22 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/e57b65abbbf7a2d5786acc86fdf56cde060ed026";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = with pkgs;
+          mkShell {
+            buildInputs = [
+              go_1_20
+              go-task
+              goreleaser
+            ];
+          };
+      });
+}

testdata/candidates/home.nix

@@ -0,0 +1,7 @@
+{ config, pkgs, ... }:
+
+{
+  # Home Manager needs a bit of information about you and the
+  # paths it should manage.
+  home.username = "kachick";
+}

testdata/candidates/shell.nix

@@ -0,0 +1,9 @@
+{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/e57b65abbbf7a2d5786acc86fdf56cde060ed026.tar.gz") { } }:
+
+pkgs.mkShell {
+  buildInputs = [
+    pkgs.go_1_20
+    pkgs.go-task
+    pkgs.goreleaser
+  ];
+}

testdata/classic/default.nix

@@ -0,0 +1,9 @@
+{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/e57b65abbbf7a2d5786acc86fdf56cde060ed026.tar.gz") { } }:
+
+pkgs.mkShell {
+  buildInputs = [
+    pkgs.go_1_20
+    pkgs.go-task
+    pkgs.goreleaser
+  ];
+}

testdata/flake/flake.nix

@@ -0,0 +1,22 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/e57b65abbbf7a2d5786acc86fdf56cde060ed026";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = with pkgs;
+          mkShell {
+            buildInputs = [
+              go_1_20
+              go-task
+              goreleaser
+            ];
+          };
+      });
+}