Demonstrate source-aware path normalization

examples/consumers/consumers.go

@@ -4,6 +4,7 @@ package consumers
 
 import (
 	"math"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -146,6 +147,69 @@ func NotariusWindow(configuration NotariusConfig, binding int) (int, bool) {
 	return int(value), true
 }
 
+// NotariusPathConfig demonstrates application-owned interpretation of a
+// path-valued configuration field. ConfigKit supplies provenance; this example
+// selects its own relative-path bases.
+type NotariusPathConfig struct {
+	Reference string `yaml:"reference"`
+	Sensitive string `yaml:"sensitive"`
+}
+
+// LoadNotariusPaths loads the path-bearing Notarius-shaped example. InvocationDir
+// is the application-supplied base for relative CLI overrides; it is never read
+// from the process working directory.
+func LoadNotariusPaths(path, invocationDir string, overrides ...configkit.Override) (*configkit.Result[NotariusPathConfig], error) {
+	return configkit.Load(configkit.File(path), configkit.Options[NotariusPathConfig]{
+		Imports: true, Overrides: overrides,
+		Definition: configkit.Definition[NotariusPathConfig]{
+			Defaults: func() NotariusPathConfig { return NotariusPathConfig{Reference: "defaults/reference.txt"} },
+			Resolve: func(configuration *NotariusPathConfig, resolution *configkit.Resolution) error {
+				resolveNotariusReference(configuration, resolution, invocationDir)
+				return nil
+			},
+			Secret: func(path configkit.Path) bool { return path.String() == "/sensitive" },
+		},
+	})
+}
+
+func resolveNotariusReference(configuration *NotariusPathConfig, resolution *configkit.Resolution, invocationDir string) {
+	path := configkit.Keys("reference")
+	if configuration.Reference == "" || filepath.IsAbs(configuration.Reference) {
+		return
+	}
+	info, found := resolution.InputInfo(path)
+	if !found {
+		resolution.Warning(path, "relative reference has no entry provenance")
+		return
+	}
+
+	base := ""
+	if info.Origin.Layer == configkit.LayerCLI {
+		base = invocationDir
+		if base == "" {
+			resolution.Warning(path, "relative CLI reference has no invocation directory")
+			return
+		}
+	} else {
+		sourceID := "source-1" // ConfigKit's primary-source identity convention.
+		if info.Origin.Layer != configkit.LayerDefault {
+			if len(info.Origin.Locations) != 1 {
+				resolution.Warning(path, "relative reference has no unambiguous declaring source")
+				return
+			}
+			sourceID = info.Origin.Locations[0].SourceID
+		}
+		source, exists := resolution.Source(sourceID)
+		if !exists || source.Path == "" {
+			resolution.Warning(path, "relative reference has no declaring file")
+			return
+		}
+		base = filepath.Dir(source.Path)
+	}
+	configkit.Normalize(resolution, path, &configuration.Reference,
+		filepath.Join(base, configuration.Reference), "resolved relative reference from entry source")
+}
+
 // ModuleOptions is a WeatherReporter-shaped union of known module option fields.
 type ModuleOptions struct {
 	WindowUnits *int     `yaml:"window_units"`

examples/consumers/consumers_test.go

@@ -29,6 +29,12 @@ func Example_notarius() {
 	// Output: 4 summary 12 true <nil>
 }
 
+func Example_notariusPaths() {
+	result, err := consumers.LoadNotariusPaths(fixture("notarius-paths", "main.yml"), "/invocation")
+	fmt.Println(filepath.Base(result.Config.Reference), err)
+	// Output: imported.txt <nil>
+}
+
 func Example_weatherReporter() {
 	defaults, defaultsErr := consumers.LoadWeather(configkit.NoSource())
 	result, err := consumers.LoadWeather(configkit.File(fixture("weather", "config.yml")))
@@ -240,12 +246,89 @@ func TestWeatherLoadedAndConstructedRulesAgreeWithoutMutation(t *testing.T) {
 	}
 }
 
+func TestNotariusPathExampleUsesEntryProvenance(t *testing.T) {
+	main := fixture("notarius-paths", "main.yml")
+	declared := fixture("notarius-paths", "declarations", "path.yml")
+	declaredCanonical := canonicalFixture(t, declared)
+	wantImported := filepath.Join(filepath.Dir(declaredCanonical), "..", "assets", "imported.txt")
+	result, err := consumers.LoadNotariusPaths(main, filepath.Join(t.TempDir(), "invocation"))
+	if err != nil || result.Config.Reference != wantImported {
+		t.Fatalf("imported reference = %#v, %v", result, err)
+	}
+	var effective bytes.Buffer
+	if err := result.WriteEffective(&effective); err != nil || !strings.Contains(effective.String(), wantImported) ||
+		strings.Contains(effective.String(), "PATH_REFERENCE_SECRET_CANARY") {
+		t.Fatalf("effective output = %q, %v", effective.String(), err)
+	}
+	explanation, found := result.Explain(configkit.Keys("reference"))
+	if !found || len(explanation.History) == 0 || explanation.History[len(explanation.History)-1].Before.YAML != "../assets/imported.txt\n" ||
+		len(explanation.History[len(explanation.History)-1].Reasons) != 1 || explanation.History[len(explanation.History)-1].Reasons[0] != "resolved relative reference from entry source" {
+		t.Fatalf("reference explanation = %#v, %v", explanation, found)
+	}
+	sensitive, found := result.Explain(configkit.Keys("sensitive"))
+	var rendered bytes.Buffer
+	writeErr := result.WriteExplanation(&rendered, configkit.Keys("sensitive"))
+	if !found || !sensitive.Effective.Redacted || writeErr != nil ||
+		strings.Contains(fmt.Sprintf("%#v %s", sensitive, rendered.String()), "PATH_REFERENCE_SECRET_CANARY") {
+		t.Fatalf("sensitive inspection = %#v, %q, %v", sensitive, rendered.String(), writeErr)
+	}
+
+	defaults := fixture("notarius-paths", "defaults.yml")
+	defaultCanonical := canonicalFixture(t, defaults)
+	defaultResult, err := consumers.LoadNotariusPaths(defaults, filepath.Join(t.TempDir(), "invocation"))
+	wantDefault := filepath.Join(filepath.Dir(defaultCanonical), "defaults", "reference.txt")
+	if err != nil || defaultResult.Config.Reference != wantDefault {
+		t.Fatalf("default reference = %#v, %v", defaultResult, err)
+	}
+
+	invocation := filepath.Join(t.TempDir(), "caller")
+	cliResult, err := consumers.LoadNotariusPaths(main, invocation,
+		configkit.Override{Path: configkit.Keys("reference"), Value: "cli/reference.txt", Flag: "--reference"})
+	wantCLI := filepath.Join(invocation, "cli", "reference.txt")
+	if err != nil || cliResult.Config.Reference != wantCLI {
+		t.Fatalf("CLI reference = %#v, %v", cliResult, err)
+	}
+	missingBase, err := consumers.LoadNotariusPaths(main, "",
+		configkit.Override{Path: configkit.Keys("reference"), Value: "cli/reference.txt", Flag: "--reference"})
+	if err != nil || missingBase.Config.Reference != "cli/reference.txt" || len(missingBase.Diagnostics()) != 1 ||
+		missingBase.Diagnostics()[0].Code != configkit.CodeResolveWarning {
+		t.Fatalf("missing CLI base = %#v, %v", missingBase, err)
+	}
+	absolute := filepath.Join(t.TempDir(), "absolute.txt")
+	absoluteResult, err := consumers.LoadNotariusPaths(main, invocation,
+		configkit.Override{Path: configkit.Keys("reference"), Value: absolute, Flag: "--reference"})
+	if err != nil || absoluteResult.Config.Reference != absolute {
+		t.Fatalf("absolute reference = %#v, %v", absoluteResult, err)
+	}
+
+	target := fixture("notarius-paths", "symlink-target.yml")
+	link := filepath.Join(t.TempDir(), "linked-config.yml")
+	if err := os.Symlink(target, link); err != nil {
+		t.Skipf("symlink fixture unavailable: %v", err)
+	}
+	symlinkResult, err := consumers.LoadNotariusPaths(link, invocation)
+	targetCanonical := canonicalFixture(t, target)
+	wantSymlink := filepath.Join(filepath.Dir(targetCanonical), "..", "assets", "target.txt")
+	if err != nil || symlinkResult.Config.Reference != wantSymlink {
+		t.Fatalf("symlink reference = %#v, %v", symlinkResult, err)
+	}
+}
+
 func fixture(parts ...string) string {
 	_, file, _, _ := runtime.Caller(0)
 	values := append([]string{filepath.Dir(file), "testdata"}, parts...)
 	return filepath.Join(values...)
 }
 
+func canonicalFixture(t *testing.T, path string) string {
+	t.Helper()
+	canonical, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return canonical
+}
+
 func preserveEnvironment(name string) func() {
 	value, present := os.LookupEnv(name)
 	return func() {

examples/consumers/testdata/notarius-paths/declarations/path.yml

@@ -0,0 +1 @@
+reference: ../assets/imported.txt

examples/consumers/testdata/notarius-paths/defaults.yml

@@ -0,0 +1 @@
+sensitive: PATH_REFERENCE_SECRET_CANARY

examples/consumers/testdata/notarius-paths/main.yml

@@ -0,0 +1,4 @@
+configkit:
+  imports:
+    - path: declarations/path.yml
+sensitive: PATH_REFERENCE_SECRET_CANARY

examples/consumers/testdata/notarius-paths/symlink-target.yml

@@ -0,0 +1,2 @@
+reference: ../assets/target.txt
+sensitive: PATH_REFERENCE_SECRET_CANARY