Merge 96a6cef0d6 into abfd1713e0

## Changes

Users can configure the bundle to not synchronize any files with:
```yaml
sync:
  paths: []
```

If it is explicitly configured as an empty list, the validate command
must not warn about not having any files to synchronize. The warning
exists to alert users who are unintentionally not synchronizing any
files (they might have a `.gitignore` pattern that matches everything).

Closes #1663.

## Tests

* New unit test.

bundle/config/experimental.go

@@ -45,6 +45,12 @@ type PyDABs struct {
 	// These packages are imported to discover resources, resource generators, and mutators.
 	// This list can include namespace packages, which causes the import of nested packages.
 	Import []string `json:"import,omitempty"`
+
+	// LoadLocations is a flag to enable loading Python source locations from the PyDABs.
+	//
+	// Locations are only supported since PyDABs 0.6.0, and because of that,
+	// this flag is disabled by default.
+	LoadLocations bool `json:"load_locations,omitempty"`
 }
 
 type Command string

bundle/config/mutator/python/python_diagnostics.go

@@ -9,6 +9,7 @@ import (
 	"github.com/databricks/cli/libs/dyn"
 )
 
+// pythonDiagnostic is a single entry in diagnostics.json
 type pythonDiagnostic struct {
 	Severity pythonSeverity           `json:"severity"`
 	Summary  string                   `json:"summary"`

bundle/config/mutator/python/python_locations.go

@@ -0,0 +1,181 @@
+package python
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"path/filepath"
+
+	"github.com/databricks/cli/libs/dyn"
+)
+
+// generatedFileName is used as the virtual file name for YAML generated by PyDABs.
+//
+// mergePythonLocations replaces dyn.Location with generatedFileName with locations loaded
+// from locations.json
+const generatedFileName = "__generated_by_pydabs__.yml"
+
+// pythonLocations is data structure for efficient location lookup for a given path
+//
+// Locations form a tree, and we assign locations of the closest ancestor to each dyn.Value based on its path.
+// We implement it as a trie (prefix tree) where keys are components of the path. With that, lookups are O(n)
+// where n is the number of components in the path.
+//
+// For example, with locations.json:
+//
+//	{"path": "resources.jobs.job_0", "file": "src/examples/job_0.py", "line": 3, "column": 5}
+//	{"path": "resources.jobs.job_0.tasks[0].task_key", "file": "src/examples/job_0.py", "line": 10, "column": 5}
+//	{"path": "resources.jobs.job_1", "file": "src/examples/job_1.py", "line": 5, "column": 7}
+//
+// - resources.jobs.job_0.tasks[0].task_key is located at job_0.py:10:5
+//
+//   - resources.jobs.job_0.tasks[0].email_notifications is located at job_0.py:3:5,
+//     because we use the location of the job as the most precise approximation.
+type pythonLocations struct {
+	// descendants referenced by index, e.g. '.foo'
+	keys map[string]*pythonLocations
+
+	// descendants referenced by key, e.g. '[0]'
+	indexes map[int]*pythonLocations
+
+	// location for the current node if it exists
+	location dyn.Location
+
+	// if true, location is present
+	exists bool
+}
+
+// pythonLocationEntry is a single entry in locations.json
+type pythonLocationEntry struct {
+	Path   string `json:"path"`
+	File   string `json:"file"`
+	Line   int    `json:"line"`
+	Column int    `json:"column"`
+}
+
+// mergePythonLocations applies locations from Python mutator into given dyn.Value
+//
+// The primary use-case is to merge locations.json with output.json, so that any
+// validation errors will point to Python source code instead of generated YAML.
+func mergePythonLocations(value dyn.Value, locations *pythonLocations) (dyn.Value, error) {
+	return dyn.Walk(value, func(path dyn.Path, value dyn.Value) (dyn.Value, error) {
+		newLocation, ok := findPythonLocation(locations, path)
+		if !ok {
+			return value, nil
+		}
+
+		var newLocations []dyn.Location
+
+		// the first item in the list is the "last" location used for error reporting
+		newLocations = append(newLocations, newLocation)
+
+		for _, location := range value.Locations() {
+			// When loaded, dyn.Value created by PyDABs use the virtual file path as their location,
+			// we replace it with newLocation.
+			if filepath.Base(location.File) == generatedFileName {
+				continue
+			}
+
+			newLocations = append(newLocations, location)
+		}
+
+		return value.WithLocations(newLocations), nil
+	})
+}
+
+// parsePythonLocations parses locations.json from the Python mutator.
+//
+// locations file is newline-separated JSON objects with pythonLocationEntry structure.
+func parsePythonLocations(input io.Reader) (*pythonLocations, error) {
+	decoder := json.NewDecoder(input)
+	locations := newPythonLocations()
+
+	for decoder.More() {
+		var entry pythonLocationEntry
+
+		err := decoder.Decode(&entry)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse python location: %s", err)
+		}
+
+		path, err := dyn.NewPathFromString(entry.Path)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse python location: %s", err)
+		}
+
+		location := dyn.Location{
+			File:   entry.File,
+			Line:   entry.Line,
+			Column: entry.Column,
+		}
+
+		putPythonLocation(locations, path, location)
+	}
+
+	return locations, nil
+}
+
+// putPythonLocation puts the location to the trie for the given path
+func putPythonLocation(trie *pythonLocations, path dyn.Path, location dyn.Location) {
+	var currentNode = trie
+
+	for _, component := range path {
+		if key := component.Key(); key != "" {
+			if _, ok := currentNode.keys[key]; !ok {
+				currentNode.keys[key] = newPythonLocations()
+			}
+
+			currentNode = currentNode.keys[key]
+		} else {
+			index := component.Index()
+			if _, ok := currentNode.indexes[index]; !ok {
+				currentNode.indexes[index] = newPythonLocations()
+			}
+
+			currentNode = currentNode.indexes[index]
+		}
+	}
+
+	currentNode.location = location
+	currentNode.exists = true
+}
+
+// newPythonLocations creates a new trie node
+func newPythonLocations() *pythonLocations {
+	return &pythonLocations{
+		keys:    make(map[string]*pythonLocations),
+		indexes: make(map[int]*pythonLocations),
+	}
+}
+
+// findPythonLocation finds the location or closest ancestor location in the trie for the given path
+// if no ancestor or exact location is found, false is returned.
+func findPythonLocation(locations *pythonLocations, path dyn.Path) (dyn.Location, bool) {
+	var currentNode = locations
+	var lastLocation = locations.location
+	var exists = locations.exists
+
+	for _, component := range path {
+		if key := component.Key(); key != "" {
+			if _, ok := currentNode.keys[key]; !ok {
+				break
+			}
+
+			currentNode = currentNode.keys[key]
+		} else {
+			index := component.Index()
+			if _, ok := currentNode.indexes[index]; !ok {
+				break
+			}
+
+			currentNode = currentNode.indexes[index]
+		}
+
+		if currentNode.exists {
+			lastLocation = currentNode.location
+			exists = true
+		}
+	}
+
+	return lastLocation, exists
+}

bundle/config/mutator/python/python_locations_test.go

@@ -0,0 +1,124 @@
+package python
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/databricks/cli/libs/dyn"
+	assert "github.com/databricks/cli/libs/dyn/dynassert"
+)
+
+func TestMergeLocations(t *testing.T) {
+	pythonLocation := dyn.Location{File: "foo.py", Line: 1, Column: 1}
+	generatedLocation := dyn.Location{File: generatedFileName, Line: 1, Column: 1}
+	yamlLocation := dyn.Location{File: "foo.yml", Line: 1, Column: 1}
+
+	locations := newPythonLocations()
+	putPythonLocation(locations, dyn.MustPathFromString("foo"), pythonLocation)
+
+	input := dyn.NewValue(
+		map[string]dyn.Value{
+			"foo": dyn.NewValue(
+				map[string]dyn.Value{
+					"baz": dyn.NewValue("baz", []dyn.Location{yamlLocation}),
+					"qux": dyn.NewValue("baz", []dyn.Location{generatedLocation, yamlLocation}),
+				},
+				[]dyn.Location{},
+			),
+			"bar": dyn.NewValue("baz", []dyn.Location{generatedLocation}),
+		},
+		[]dyn.Location{yamlLocation},
+	)
+
+	expected := dyn.NewValue(
+		map[string]dyn.Value{
+			"foo": dyn.NewValue(
+				map[string]dyn.Value{
+					// pythonLocation is appended to the beginning of the list if absent
+					"baz": dyn.NewValue("baz", []dyn.Location{pythonLocation, yamlLocation}),
+					// generatedLocation is replaced by pythonLocation
+					"qux": dyn.NewValue("baz", []dyn.Location{pythonLocation, yamlLocation}),
+				},
+				[]dyn.Location{pythonLocation},
+			),
+			// if location is unknown, we keep it as-is
+			"bar": dyn.NewValue("baz", []dyn.Location{generatedLocation}),
+		},
+		[]dyn.Location{yamlLocation},
+	)
+
+	actual, err := mergePythonLocations(input, locations)
+
+	assert.NoError(t, err)
+	assert.Equal(t, expected, actual)
+}
+
+func TestFindLocation(t *testing.T) {
+	location0 := dyn.Location{File: "foo.py", Line: 1, Column: 1}
+	location1 := dyn.Location{File: "foo.py", Line: 2, Column: 1}
+
+	locations := newPythonLocations()
+	putPythonLocation(locations, dyn.MustPathFromString("foo"), location0)
+	putPythonLocation(locations, dyn.MustPathFromString("foo.bar"), location1)
+
+	actual, exists := findPythonLocation(locations, dyn.MustPathFromString("foo.bar"))
+
+	assert.True(t, exists)
+	assert.Equal(t, location1, actual)
+}
+
+func TestFindLocation_indexPathComponent(t *testing.T) {
+	location0 := dyn.Location{File: "foo.py", Line: 1, Column: 1}
+	location1 := dyn.Location{File: "foo.py", Line: 2, Column: 1}
+	location2 := dyn.Location{File: "foo.py", Line: 3, Column: 1}
+
+	locations := newPythonLocations()
+	putPythonLocation(locations, dyn.MustPathFromString("foo"), location0)
+	putPythonLocation(locations, dyn.MustPathFromString("foo.bar"), location1)
+	putPythonLocation(locations, dyn.MustPathFromString("foo.bar[0]"), location2)
+
+	actual, exists := findPythonLocation(locations, dyn.MustPathFromString("foo.bar[0]"))
+
+	assert.True(t, exists)
+	assert.Equal(t, location2, actual)
+}
+
+func TestFindLocation_closestAncestorLocation(t *testing.T) {
+	location0 := dyn.Location{File: "foo.py", Line: 1, Column: 1}
+	location1 := dyn.Location{File: "foo.py", Line: 2, Column: 1}
+
+	locations := newPythonLocations()
+	putPythonLocation(locations, dyn.MustPathFromString("foo"), location0)
+	putPythonLocation(locations, dyn.MustPathFromString("foo.bar"), location1)
+
+	actual, exists := findPythonLocation(locations, dyn.MustPathFromString("foo.bar.baz"))
+
+	assert.True(t, exists)
+	assert.Equal(t, location1, actual)
+}
+
+func TestFindLocation_unknownLocation(t *testing.T) {
+	location0 := dyn.Location{File: "foo.py", Line: 1, Column: 1}
+	location1 := dyn.Location{File: "foo.py", Line: 2, Column: 1}
+
+	locations := newPythonLocations()
+	putPythonLocation(locations, dyn.MustPathFromString("foo"), location0)
+	putPythonLocation(locations, dyn.MustPathFromString("foo.bar"), location1)
+
+	_, exists := findPythonLocation(locations, dyn.MustPathFromString("bar"))
+
+	assert.False(t, exists)
+}
+
+func TestParsePythonLocations(t *testing.T) {
+	expected := dyn.Location{File: "foo.py", Line: 1, Column: 2}
+
+	input := `{"path": "foo", "file": "foo.py", "line": 1, "column": 2}`
+	reader := bytes.NewReader([]byte(input))
+	locations, err := parsePythonLocations(reader)
+
+	assert.NoError(t, err)
+
+	assert.True(t, locations.keys["foo"].exists)
+	assert.Equal(t, expected, locations.keys["foo"].location)
+}

bundle/config/mutator/python/python_mutator.go

@@ -7,9 +7,12 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/fs"
 	"os"
 	"path/filepath"
 
+	"github.com/databricks/cli/bundle/config/mutator/paths"
+
 	"github.com/databricks/databricks-sdk-go/logger"
 	"github.com/fatih/color"
 
@@ -108,7 +111,12 @@ func (m *pythonMutator) Apply(ctx context.Context, b *bundle.Bundle) diag.Diagno
 			return dyn.InvalidValue, fmt.Errorf("failed to create cache dir: %w", err)
 		}
 
-		rightRoot, diags := m.runPythonMutator(ctx, cacheDir, b.BundleRootPath, pythonPath, leftRoot)
+		rightRoot, diags := m.runPythonMutator(ctx, leftRoot, runPythonMutatorOpts{
+			cacheDir:       cacheDir,
+			bundleRootPath: b.BundleRootPath,
+			pythonPath:     pythonPath,
+			loadLocations:  experimental.PyDABs.LoadLocations,
+		})
 		mutateDiags = diags
 		if diags.HasError() {
 			return dyn.InvalidValue, mutateDiagsHasError
@@ -152,13 +160,21 @@ func createCacheDir(ctx context.Context) (string, error) {
 	return os.MkdirTemp("", "-pydabs")
 }
 
-func (m *pythonMutator) runPythonMutator(ctx context.Context, cacheDir string, rootPath string, pythonPath string, root dyn.Value) (dyn.Value, diag.Diagnostics) {
-	inputPath := filepath.Join(cacheDir, "input.json")
-	outputPath := filepath.Join(cacheDir, "output.json")
-	diagnosticsPath := filepath.Join(cacheDir, "diagnostics.json")
+type runPythonMutatorOpts struct {
+	cacheDir       string
+	bundleRootPath string
+	pythonPath     string
+	loadLocations  bool
+}
+
+func (m *pythonMutator) runPythonMutator(ctx context.Context, root dyn.Value, opts runPythonMutatorOpts) (dyn.Value, diag.Diagnostics) {
+	inputPath := filepath.Join(opts.cacheDir, "input.json")
+	outputPath := filepath.Join(opts.cacheDir, "output.json")
+	diagnosticsPath := filepath.Join(opts.cacheDir, "diagnostics.json")
+	locationsPath := filepath.Join(opts.cacheDir, "locations.json")
 
 	args := []string{
-		pythonPath,
+		opts.pythonPath,
 		"-m",
 		"databricks.bundles.build",
 		"--phase",
@@ -171,6 +187,10 @@ func (m *pythonMutator) runPythonMutator(ctx context.Context, cacheDir string, r
 		diagnosticsPath,
 	}
 
+	if opts.loadLocations {
+		args = append(args, "--locations", locationsPath)
+	}
+
 	if err := writeInputFile(inputPath, root); err != nil {
 		return dyn.InvalidValue, diag.Errorf("failed to write input file: %s", err)
 	}
@@ -185,7 +205,7 @@ func (m *pythonMutator) runPythonMutator(ctx context.Context, cacheDir string, r
 	_, processErr := process.Background(
 		ctx,
 		args,
-		process.WithDir(rootPath),
+		process.WithDir(opts.bundleRootPath),
 		process.WithStderrWriter(stderrWriter),
 		process.WithStdoutWriter(stdoutWriter),
 	)
@@ -221,7 +241,12 @@ func (m *pythonMutator) runPythonMutator(ctx context.Context, cacheDir string, r
 		return dyn.InvalidValue, diag.Errorf("failed to load diagnostics: %s", pythonDiagnosticsErr)
 	}
 
-	output, outputDiags := loadOutputFile(rootPath, outputPath)
+	locations, err := loadLocationsFile(locationsPath)
+	if err != nil {
+		return dyn.InvalidValue, diag.Errorf("failed to load locations: %s", err)
+	}
+
+	output, outputDiags := loadOutputFile(opts.bundleRootPath, outputPath, locations)
 	pythonDiagnostics = pythonDiagnostics.Extend(outputDiags)
 
 	// we pass through pythonDiagnostic because it contains warnings
@@ -266,7 +291,21 @@ func writeInputFile(inputPath string, input dyn.Value) error {
 	return os.WriteFile(inputPath, rootConfigJson, 0600)
 }
 
-func loadOutputFile(rootPath string, outputPath string) (dyn.Value, diag.Diagnostics) {
+// loadLocationsFile loads locations.json containing source locations for generated YAML.
+func loadLocationsFile(locationsPath string) (*pythonLocations, error) {
+	locationsFile, err := os.Open(locationsPath)
+	if errors.Is(err, fs.ErrNotExist) {
+		return newPythonLocations(), nil
+	} else if err != nil {
+		return nil, fmt.Errorf("failed to open locations file: %w", err)
+	}
+
+	defer locationsFile.Close()
+
+	return parsePythonLocations(locationsFile)
+}
+
+func loadOutputFile(rootPath string, outputPath string, locations *pythonLocations) (dyn.Value, diag.Diagnostics) {
 	outputFile, err := os.Open(outputPath)
 	if err != nil {
 		return dyn.InvalidValue, diag.FromErr(fmt.Errorf("failed to open output file: %w", err))
@@ -277,12 +316,12 @@ func loadOutputFile(rootPath string, outputPath string) (dyn.Value, diag.Diagnos
 	// we need absolute path because later parts of pipeline assume all paths are absolute
 	// and this file will be used as location to resolve relative paths.
 	//
-	// virtualPath has to stay in rootPath, because locations outside root path are not allowed:
+	// virtualPath has to stay in bundleRootPath, because locations outside root path are not allowed:
 	//
 	//   Error: path /var/folders/.../pydabs/dist/*.whl is not contained in bundle root path
 	//
 	// for that, we pass virtualPath instead of outputPath as file location
-	virtualPath, err := filepath.Abs(filepath.Join(rootPath, "__generated_by_pydabs__.yml"))
+	virtualPath, err := filepath.Abs(filepath.Join(rootPath, generatedFileName))
 	if err != nil {
 		return dyn.InvalidValue, diag.FromErr(fmt.Errorf("failed to get absolute path: %w", err))
 	}
@@ -292,7 +331,25 @@ func loadOutputFile(rootPath string, outputPath string) (dyn.Value, diag.Diagnos
 		return dyn.InvalidValue, diag.FromErr(fmt.Errorf("failed to parse output file: %w", err))
 	}
 
-	return strictNormalize(config.Root{}, generated)
+	// paths are resolved relative to locations of their values, if we change location
+	// we have to update each path, until we simplify that, we don't update locations
+	// for such values, so we don't change how paths are resolved
+	_, err = paths.VisitJobPaths(generated, func(p dyn.Path, kind paths.PathKind, v dyn.Value) (dyn.Value, error) {
+		putPythonLocation(locations, p, v.Location())
+		return v, nil
+	})
+	if err != nil {
+		return dyn.InvalidValue, diag.FromErr(fmt.Errorf("failed to update locations: %w", err))
+	}
+
+	// generated has dyn.Location as if it comes from generated YAML file
+	// earlier we loaded locations.json with source locations in Python code
+	generatedWithLocations, err := mergePythonLocations(generated, locations)
+	if err != nil {
+		return dyn.InvalidValue, diag.FromErr(fmt.Errorf("failed to update locations: %w", err))
+	}
+
+	return strictNormalize(config.Root{}, generatedWithLocations)
 }
 
 func strictNormalize(dst any, generated dyn.Value) (dyn.Value, diag.Diagnostics) {

bundle/config/mutator/python/python_mutator_test.go

@@ -6,7 +6,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"reflect"
 	"runtime"
 	"testing"
 
@@ -47,6 +46,7 @@ func TestPythonMutator_load(t *testing.T) {
         pydabs:
           enabled: true
           venv_path: .venv
+          load_locations: true
       resources:
         jobs:
           job0:
@@ -65,7 +65,8 @@ func TestPythonMutator_load(t *testing.T) {
 			"experimental": {
 				"pydabs": {
 					"enabled": true,
-					"venv_path": ".venv"
+					"venv_path": ".venv",
+					"load_locations": true
 				}
 			},
 			"resources": {
@@ -80,6 +81,8 @@ func TestPythonMutator_load(t *testing.T) {
 			}
 		}`,
 		`{"severity": "warning", "summary": "job doesn't have any tasks", "location": {"file": "src/examples/file.py", "line": 10, "column": 5}}`,
+		`{"path": "resources.jobs.job0", "file": "src/examples/job0.py", "line": 3, "column": 5}
+		{"path": "resources.jobs.job1", "file": "src/examples/job1.py", "line": 5, "column": 7}`,
 	)
 
 	mutator := PythonMutator(PythonMutatorPhaseLoad)
@@ -97,6 +100,25 @@ func TestPythonMutator_load(t *testing.T) {
 		assert.Equal(t, "job_1", job1.Name)
 	}
 
+	// output of locations.json should be applied to underlying dyn.Value
+	err := b.Config.Mutate(func(v dyn.Value) (dyn.Value, error) {
+		name1, err := dyn.GetByPath(v, dyn.MustPathFromString("resources.jobs.job1.name"))
+		if err != nil {
+			return dyn.InvalidValue, err
+		}
+
+		assert.Equal(t, []dyn.Location{
+			{
+				File:   "src/examples/job1.py",
+				Line:   5,
+				Column: 7,
+			},
+		}, name1.Locations())
+
+		return v, nil
+	})
+	assert.NoError(t, err)
+
 	assert.Equal(t, 1, len(diags))
 	assert.Equal(t, "job doesn't have any tasks", diags[0].Summary)
 	assert.Equal(t, []dyn.Location{
@@ -106,7 +128,6 @@ func TestPythonMutator_load(t *testing.T) {
 			Column: 5,
 		},
 	}, diags[0].Locations)
-
 }
 
 func TestPythonMutator_load_disallowed(t *testing.T) {
@@ -146,7 +167,7 @@ func TestPythonMutator_load_disallowed(t *testing.T) {
 					}
 				}
 			}
-		}`, "")
+		}`, "", "")
 
 	mutator := PythonMutator(PythonMutatorPhaseLoad)
 	diag := bundle.Apply(ctx, b, mutator)
@@ -191,7 +212,7 @@ func TestPythonMutator_init(t *testing.T) {
 					}
 				}
 			}
-		}`, "")
+		}`, "", "")
 
 	mutator := PythonMutator(PythonMutatorPhaseInit)
 	diag := bundle.Apply(ctx, b, mutator)
@@ -252,7 +273,7 @@ func TestPythonMutator_badOutput(t *testing.T) {
 					}
 				}
 			}
-		}`, "")
+		}`, "", "")
 
 	mutator := PythonMutator(PythonMutatorPhaseLoad)
 	diag := bundle.Apply(ctx, b, mutator)
@@ -588,7 +609,7 @@ or activate the environment before running CLI commands:
 	assert.Equal(t, expected, out)
 }
 
-func withProcessStub(t *testing.T, args []string, output string, diagnostics string) context.Context {
+func withProcessStub(t *testing.T, args []string, output string, diagnostics string, locations string) context.Context {
 	ctx := context.Background()
 	ctx, stub := process.WithStub(ctx)
 
@@ -600,32 +621,51 @@ func withProcessStub(t *testing.T, args []string, output string, diagnostics str
 
 	inputPath := filepath.Join(cacheDir, "input.json")
 	outputPath := filepath.Join(cacheDir, "output.json")
+	locationsPath := filepath.Join(cacheDir, "locations.json")
 	diagnosticsPath := filepath.Join(cacheDir, "diagnostics.json")
 
-	args = append(args, "--input", inputPath)
-	args = append(args, "--output", outputPath)
-	args = append(args, "--diagnostics", diagnosticsPath)
-
 	stub.WithCallback(func(actual *exec.Cmd) error {
 		_, err := os.Stat(inputPath)
 		assert.NoError(t, err)
 
-		if reflect.DeepEqual(actual.Args, args) {
-			err := os.WriteFile(outputPath, []byte(output), 0600)
-			require.NoError(t, err)
+		actualInputPath := getArg(actual.Args, "--input")
+		actualOutputPath := getArg(actual.Args, "--output")
+		actualDiagnosticsPath := getArg(actual.Args, "--diagnostics")
+		actualLocationsPath := getArg(actual.Args, "--locations")
 
-			err = os.WriteFile(diagnosticsPath, []byte(diagnostics), 0600)
-			require.NoError(t, err)
+		require.Equal(t, inputPath, actualInputPath)
+		require.Equal(t, outputPath, actualOutputPath)
+		require.Equal(t, diagnosticsPath, actualDiagnosticsPath)
 
-			return nil
-		} else {
-			return fmt.Errorf("unexpected command: %v", actual.Args)
+		// locations is an optional argument
+		if locations != "" {
+			require.Equal(t, locationsPath, actualLocationsPath)
+
+			err = os.WriteFile(locationsPath, []byte(locations), 0600)
+			require.NoError(t, err)
 		}
+
+		err = os.WriteFile(outputPath, []byte(output), 0600)
+		require.NoError(t, err)
+
+		err = os.WriteFile(diagnosticsPath, []byte(diagnostics), 0600)
+		require.NoError(t, err)
+
+		return nil
 	})
 
 	return ctx
 }
 
+func getArg(args []string, name string) string {
+	for i := 0; i < len(args); i++ {
+		if args[i] == name {
+			return args[i+1]
+		}
+	}
+	return ""
+}
+
 func loadYaml(name string, content string) *bundle.Bundle {
 	v, diag := config.LoadFromBytes(name, []byte(content))
 

bundle/config/validate/files_to_sync.go

@@ -21,6 +21,12 @@ func (v *filesToSync) Name() string {
 }
 
 func (v *filesToSync) Apply(ctx context.Context, rb bundle.ReadOnlyBundle) diag.Diagnostics {
+	// The user may be intentional about not synchronizing any files.
+	// In this case, we should not show any warnings.
+	if len(rb.Config().Sync.Paths) == 0 {
+		return nil
+	}
+
 	sync, err := files.GetSync(ctx, rb)
 	if err != nil {
 		return diag.FromErr(err)
@@ -31,6 +37,7 @@ func (v *filesToSync) Apply(ctx context.Context, rb bundle.ReadOnlyBundle) diag.
 		return diag.FromErr(err)
 	}
 
+	// If there are files to sync, we don't need to show any warnings.
 	if len(fl) != 0 {
 		return nil
 	}

bundle/config/validate/files_to_sync_test.go

@@ -0,0 +1,105 @@
+package validate
+
+import (
+	"context"
+	"testing"
+
+	"github.com/databricks/cli/bundle"
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/internal/testutil"
+	"github.com/databricks/cli/libs/diag"
+	"github.com/databricks/cli/libs/vfs"
+	sdkconfig "github.com/databricks/databricks-sdk-go/config"
+	"github.com/databricks/databricks-sdk-go/experimental/mocks"
+	"github.com/databricks/databricks-sdk-go/service/iam"
+	"github.com/databricks/databricks-sdk-go/service/workspace"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFilesToSync_NoPaths(t *testing.T) {
+	b := &bundle.Bundle{
+		Config: config.Root{
+			Sync: config.Sync{
+				Paths: []string{},
+			},
+		},
+	}
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	assert.Empty(t, diags)
+}
+
+func setupBundleForFilesToSyncTest(t *testing.T) *bundle.Bundle {
+	dir := t.TempDir()
+
+	testutil.Touch(t, dir, "file1")
+	testutil.Touch(t, dir, "file2")
+
+	b := &bundle.Bundle{
+		BundleRootPath: dir,
+		BundleRoot:     vfs.MustNew(dir),
+		SyncRootPath:   dir,
+		SyncRoot:       vfs.MustNew(dir),
+		Config: config.Root{
+			Bundle: config.Bundle{
+				Target: "default",
+			},
+			Workspace: config.Workspace{
+				FilePath: "/this/doesnt/matter",
+				CurrentUser: &config.User{
+					User: &iam.User{},
+				},
+			},
+			Sync: config.Sync{
+				// Paths are relative to [SyncRootPath].
+				Paths: []string{"."},
+			},
+		},
+	}
+
+	m := mocks.NewMockWorkspaceClient(t)
+	m.WorkspaceClient.Config = &sdkconfig.Config{
+		Host: "https://foo.com",
+	}
+
+	// The initialization logic in [sync.New] performs a check on the destination path.
+	// Removing this check at initialization time is tbd...
+	m.GetMockWorkspaceAPI().EXPECT().GetStatusByPath(mock.Anything, "/this/doesnt/matter").Return(&workspace.ObjectInfo{
+		ObjectType: workspace.ObjectTypeDirectory,
+	}, nil)
+
+	b.SetWorkpaceClient(m.WorkspaceClient)
+	return b
+}
+
+func TestFilesToSync_EverythingIgnored(t *testing.T) {
+	b := setupBundleForFilesToSyncTest(t)
+
+	// Ignore all files.
+	testutil.WriteFile(t, "*\n.*\n", b.BundleRootPath, ".gitignore")
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	require.Equal(t, 1, len(diags))
+	assert.Equal(t, diag.Warning, diags[0].Severity)
+	assert.Equal(t, "There are no files to sync, please check your .gitignore", diags[0].Summary)
+}
+
+func TestFilesToSync_EverythingExcluded(t *testing.T) {
+	b := setupBundleForFilesToSyncTest(t)
+
+	// Exclude all files.
+	b.Config.Sync.Exclude = []string{"*"}
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	require.Equal(t, 1, len(diags))
+	assert.Equal(t, diag.Warning, diags[0].Severity)
+	assert.Equal(t, "There are no files to sync, please check your .gitignore and sync.exclude configuration", diags[0].Summary)
+}

bundle/config/variable/lookup.go

@@ -22,6 +22,8 @@ type Lookup struct {
 
 	Metastore string `json:"metastore,omitempty"`
 
+	NotificationDestination string `json:"notification_destination,omitempty"`
+
 	Pipeline string `json:"pipeline,omitempty"`
 
 	Query string `json:"query,omitempty"`
@@ -63,6 +65,9 @@ func (l *Lookup) constructResolver() (resolver, error) {
 	if l.Metastore != "" {
 		resolvers = append(resolvers, resolveMetastore{name: l.Metastore})
 	}
+	if l.NotificationDestination != "" {
+		resolvers = append(resolvers, resolveNotificationDestination{name: l.NotificationDestination})
+	}
 	if l.Pipeline != "" {
 		resolvers = append(resolvers, resolvePipeline{name: l.Pipeline})
 	}

bundle/config/variable/resolve_notification_destination.go

@@ -0,0 +1,46 @@
+package variable
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/databricks/databricks-sdk-go"
+	"github.com/databricks/databricks-sdk-go/service/settings"
+)
+
+type resolveNotificationDestination struct {
+	name string
+}
+
+func (l resolveNotificationDestination) Resolve(ctx context.Context, w *databricks.WorkspaceClient) (string, error) {
+	result, err := w.NotificationDestinations.ListAll(ctx, settings.ListNotificationDestinationsRequest{
+		// The default page size for this API is 20.
+		// We use a higher value to make fewer API calls.
+		PageSize: 200,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	// Collect all notification destinations with the given name.
+	var entities []settings.ListNotificationDestinationsResult
+	for _, entity := range result {
+		if entity.DisplayName == l.name {
+			entities = append(entities, entity)
+		}
+	}
+
+	// Return the ID of the first matching notification destination.
+	switch len(entities) {
+	case 0:
+		return "", fmt.Errorf("notification destination named %q does not exist", l.name)
+	case 1:
+		return entities[0].Id, nil
+	default:
+		return "", fmt.Errorf("there are %d instances of clusters named %q", len(entities), l.name)
+	}
+}
+
+func (l resolveNotificationDestination) String() string {
+	return fmt.Sprintf("notification-destination: %s", l.name)
+}

bundle/config/variable/resolve_notification_destination_test.go

@@ -0,0 +1,82 @@
+package variable
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/databricks/databricks-sdk-go/experimental/mocks"
+	"github.com/databricks/databricks-sdk-go/service/settings"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestResolveNotificationDestination_ResolveSuccess(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{
+			{Id: "1234", DisplayName: "destination"},
+		}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	result, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.NoError(t, err)
+	assert.Equal(t, "1234", result)
+}
+
+func TestResolveNotificationDestination_ResolveError(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return(nil, fmt.Errorf("bad"))
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	assert.ErrorContains(t, err, "bad")
+}
+
+func TestResolveNotificationDestination_ResolveNotFound(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.Error(t, err)
+	assert.ErrorContains(t, err, `notification destination named "destination" does not exist`)
+}
+
+func TestResolveNotificationDestination_ResolveMultiple(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{
+			{Id: "1234", DisplayName: "destination"},
+			{Id: "5678", DisplayName: "destination"},
+		}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.Error(t, err)
+	assert.ErrorContains(t, err, `there are 2 instances of clusters named "destination"`)
+}
+
+func TestResolveNotificationDestination_String(t *testing.T) {
+	l := resolveNotificationDestination{name: "name"}
+	assert.Equal(t, "notification-destination: name", l.String())
+}