more iteration

bundle/internal/bundle/schema/main.go

@@ -1,42 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"log"
-	"os"
-
-	"github.com/databricks/cli/bundle/schema"
-)
-
-func main() {
-	if len(os.Args) != 2 {
-		fmt.Println("Usage: go run main.go <output-file>")
-		os.Exit(1)
-	}
-
-	// Output file, to write the generated schema descriptions to.
-	outputFile := os.Args[1]
-
-	// Input file, the databricks openapi spec.
-	inputFile := os.Getenv("DATABRICKS_OPENAPI_SPEC")
-	if inputFile == "" {
-		log.Fatal("DATABRICKS_OPENAPI_SPEC environment variable not set")
-	}
-
-	// Generate the schema descriptions.
-	docs, err := schema.UpdateBundleDescriptions(inputFile)
-	if err != nil {
-		log.Fatal(err)
-	}
-	result, err := json.MarshalIndent(docs, "", "  ")
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	// Write the schema descriptions to the output file.
-	err = os.WriteFile(outputFile, result, 0644)
-	if err != nil {
-		log.Fatal(err)
-	}
-}

bundle/internal/schema/main.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/libs/jsonschema"
+)
+
+func interpolationPattern(s string) string {
+	return fmt.Sprintf(`\$\{(%s(\.[a-zA-Z]+([-_]?[a-zA-Z0-9]+)*(\[[0-9]+\])*)*(\[[0-9]+\])*)\}`, s)
+}
+
+func addInterpolationPatterns(_ reflect.Type, s jsonschema.Schema) jsonschema.Schema {
+	switch s.Type {
+	case jsonschema.ArrayType, jsonschema.ObjectType:
+		// arrays and objects can have complex variable values specified.
+		return jsonschema.Schema{
+			AnyOf: []jsonschema.Schema{s, {
+				Type: jsonschema.StringType,
+				// TODO: Are multi-level complex variable references supported?
+				Pattern: interpolationPattern("var"),
+			}},
+		}
+	case jsonschema.StringType, jsonschema.IntegerType, jsonschema.NumberType, jsonschema.BooleanType:
+		// primitives can have variable values, or references like ${bundle.xyz}
+		// or ${workspace.xyz}
+		// TODO: Followup, do not allow references like ${} in the schema unless
+		// they are of the permitted patterns?
+		return jsonschema.Schema{
+			AnyOf: []jsonschema.Schema{s,
+				// TODO: Add "resources" here
+				{Type: jsonschema.StringType, Pattern: interpolationPattern("bundle")},
+				{Type: jsonschema.StringType, Pattern: interpolationPattern("workspace")},
+				{Type: jsonschema.StringType, Pattern: interpolationPattern("var")},
+			},
+		}
+	default:
+		return s
+	}
+}
+
+// TODO: Add a couple of end to end tests that the bundle schema generated is
+// correct.
+// TODO: Call out in the PR description that recursive types like "for_each_task"
+// are now supported. Manually test for_each_task.
+// TODO: The bundle_descriptions.json file contains a bunch of custom descriptions
+// as well. Make sure to pull those in.
+// TODO: Add unit tests for all permutations of structs, maps and slices for the FromType
+// method.
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Println("Usage: go run main.go <output-file>")
+		os.Exit(1)
+	}
+
+	// Output file, where the generated JSON schema will be written to.
+	outputFile := os.Args[1]
+
+	// Input file, the databricks openapi spec.
+	inputFile := os.Getenv("DATABRICKS_OPENAPI_SPEC")
+	if inputFile == "" {
+		log.Fatal("DATABRICKS_OPENAPI_SPEC environment variable not set")
+	}
+
+	p, err := newParser(inputFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Generate the JSON schema from the bundle Go struct.
+	s, err := jsonschema.FromType(reflect.TypeOf(config.Root{}), []func(reflect.Type, jsonschema.Schema) jsonschema.Schema{
+		p.addDescriptions,
+		p.addEnums,
+		addInterpolationPatterns,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	b, err := json.MarshalIndent(s, "", "  ")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Write the schema descriptions to the output file.
+	err = os.WriteFile(outputFile, b, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+}

bundle/internal/schema/parser.go

@@ -0,0 +1,131 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path"
+	"reflect"
+	"strings"
+
+	"github.com/databricks/cli/libs/jsonschema"
+)
+
+type Components struct {
+	Schemas map[string]jsonschema.Schema `json:"schemas,omitempty"`
+}
+
+type Specification struct {
+	Components Components `json:"components"`
+}
+
+type openapiParser struct {
+	ref map[string]jsonschema.Schema
+}
+
+func newParser(path string) (*openapiParser, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	spec := Specification{}
+	err = json.Unmarshal(b, &spec)
+	if err != nil {
+		return nil, err
+	}
+
+	p := &openapiParser{}
+	p.ref = spec.Components.Schemas
+	return p, nil
+}
+
+// This function finds any JSON schemas that were defined in the OpenAPI spec
+// that correspond to the given Go SDK type. It looks both at the type itself
+// and any embedded types within it.
+func (p *openapiParser) findRef(typ reflect.Type) (jsonschema.Schema, bool) {
+	typs := []reflect.Type{typ}
+
+	// If the type is a struct, the corresponding Go SDK struct might be embedded
+	// in it. We need to check for those as well.
+	if typ.Kind() == reflect.Struct {
+		for i := 0; i < typ.NumField(); i++ {
+			if !typ.Field(i).Anonymous {
+				continue
+			}
+
+			// Deference current type if it's a pointer.
+			ctyp := typ.Field(i).Type
+			for ctyp.Kind() == reflect.Ptr {
+				ctyp = ctyp.Elem()
+			}
+
+			typs = append(typs, ctyp)
+		}
+	}
+
+	for _, ctyp := range typs {
+		// Skip if it's not a Go SDK type.
+		if !strings.HasPrefix(ctyp.PkgPath(), "github.com/databricks/databricks-sdk-go") {
+			continue
+		}
+
+		pkgName := path.Base(ctyp.PkgPath())
+		k := fmt.Sprintf("%s.%s", pkgName, ctyp.Name())
+
+		// Skip if the type is not in the openapi spec.
+		_, ok := p.ref[k]
+		if !ok {
+			continue
+		}
+
+		// Return the first Go SDK type found in the openapi spec.
+		return p.ref[k], true
+	}
+
+	return jsonschema.Schema{}, false
+}
+
+// Use the OpenAPI spec to load descriptions for the given type.
+func (p *openapiParser) addDescriptions(typ reflect.Type, s jsonschema.Schema) jsonschema.Schema {
+	ref, ok := p.findRef(typ)
+	if !ok {
+		return s
+	}
+
+	s.Description = ref.Description
+
+	// Iterate over properties to load descriptions. This is not needed for any
+	// OpenAPI spec generated from protobufs, which are guaranteed to be one level
+	// deep.
+	// Needed for any hand-written OpenAPI specs.
+	for k, v := range s.Properties {
+		if refProp, ok := ref.Properties[k]; ok {
+			v.Description = refProp.Description
+		}
+	}
+
+	return s
+}
+
+// Use the OpenAPI spec add enum values for the given type.
+func (p *openapiParser) addEnums(typ reflect.Type, s jsonschema.Schema) jsonschema.Schema {
+	ref, ok := p.findRef(typ)
+	if !ok {
+		return s
+	}
+
+	s.Enum = append(s.Enum, ref.Enum...)
+
+	// Iterate over properties to load enums. This is not needed for any
+	// OpenAPI spec generated from protobufs, which are guaranteed to be one level
+	// deep.
+	// Needed for any hand-written OpenAPI specs.
+	for k, v := range s.Properties {
+		if refProp, ok := ref.Properties[k]; ok {
+			v.Enum = append(v.Enum, refProp.Enum...)
+		}
+	}
+
+	return s
+}

bundle/schema/schema.go

@@ -3,7 +3,6 @@ package schema
 import (
 	"reflect"
 
-	"github.com/databricks/cli/libs/dyn/dynvar"
 	"github.com/databricks/cli/libs/jsonschema"
 )
 
@@ -42,26 +41,28 @@ import (
 //     for details visit: https://json-schema.org/understanding-json-schema/reference/object.html#properties
 func New(golangType reflect.Type, docs *Docs) (*jsonschema.Schema, error) {
 
-	s, err := jsonschema.FromType(golangType, func(s jsonschema.Schema) jsonschema.Schema {
+	return nil, nil
-		if s.Type == jsonschema.NumberType || s.Type == jsonschema.BooleanType {
+
-			s = jsonschema.Schema{
+	// s, err := jsonschema.FromType(golangType, func(s jsonschema.Schema) jsonschema.Schema {
-				AnyOf: []jsonschema.Schema{
+	// 	if s.Type == jsonschema.NumberType || s.Type == jsonschema.BooleanType {
-					s,
+	// 		s = jsonschema.Schema{
-					{
+	// 			AnyOf: []jsonschema.Schema{
-						Type: jsonschema.StringType,
+	// 				s,
-						// TODO: Narrow down the scope of the regex match.
+	// 				{
-						// Also likely need to rename this variable.
+	// 					Type: jsonschema.StringType,
-						Pattern: dynvar.VariableRegex,
+	// 					// TODO: Narrow down the scope of the regex match.
-					},
+	// 					// Also likely need to rename this variable.
-				},
+	// 					Pattern: dynvar.ReferenceRegex,
-			}
+	// 				},
-		}
+	// 			},
-		return s
+	// 		}
-	})
+	// 	}
-	if err != nil {
+	// 	return s
-		return nil, err
+	// })
-	}
+	// if err != nil {
-	return &s, nil
+	// 	return nil, err
+	// }
+	// return &s, nil
 
 	// tracker := newTracker()
 	// schema, err := safeToSchema(golangType, docs, "", tracker)

libs/dyn/dynvar/ref.go

@@ -6,9 +6,9 @@ import (
 	"github.com/databricks/cli/libs/dyn"
 )
 
-const VariableRegex = `\$\{([a-zA-Z]+([-_]?[a-zA-Z0-9]+)*(\.[a-zA-Z]+([-_]?[a-zA-Z0-9]+)*(\[[0-9]+\])*)*(\[[0-9]+\])*)\}`
+const ReferenceRegex = `\$\{([a-zA-Z]+([-_]?[a-zA-Z0-9]+)*(\.[a-zA-Z]+([-_]?[a-zA-Z0-9]+)*(\[[0-9]+\])*)*(\[[0-9]+\])*)\}`
 
-var re = regexp.MustCompile(VariableRegex)
+var re = regexp.MustCompile(ReferenceRegex)
 
 // ref represents a variable reference.
 // It is a string [dyn.Value] contained in a larger [dyn.Value].

libs/jsonschema/from_type.go

@@ -3,17 +3,13 @@ package jsonschema
 import (
 	"container/list"
 	"fmt"
+	"maps"
 	"path"
 	"reflect"
 	"slices"
 	"strings"
 )
 
-// TODO: Maybe can be removed?
-var InvalidSchema = Schema{
-	Type: InvalidType,
-}
-
 // Fields tagged "readonly" should not be emitted in the schema as they are
 // computed at runtime, and should not be assigned a value by the bundle author.
 const readonlyTag = "readonly"
@@ -26,19 +22,17 @@ const internalTag = "internal"
 // Fields tagged as "deprecated" are removed/omitted from the generated schema.
 const deprecatedTag = "deprecated"
 
-// TODO: Test what happens with invalid cycles? Do integration tests fail?
-// TODO: Call out in the PR description that recursive types like "for_each_task"
-// are now supported.
-
 type constructor struct {
 	// Map of typ.PkgPath() + "." + typ.Name() to the schema for that type.
 	// Example key: github.com/databricks/databricks-sdk-go/service/jobs.JobSettings
 	definitions map[string]Schema
 
-	seen map[string]struct{}
+	// Map of typ.PkgPath() + "." + typ.Name() to the corresponding type. Used to
+	// track types that have been seen to avoid infinite recursion.
+	seen map[string]reflect.Type
 
-	// Transformation function to apply after generating a node in the schema.
+	// The root type for which the schema is being generated.
-	fn func(s Schema) Schema
+	root reflect.Type
 }
 
 // The $defs block in a JSON schema cannot contain "/", otherwise it will not be
@@ -47,13 +41,19 @@ type constructor struct {
 //
 // For example:
 // {"a/b/c": "value"} is converted to {"a": {"b": {"c": "value"}}}
-func (c *constructor) nestedDefinitions() any {
+func (c *constructor) Definitions() any {
-	if len(c.definitions) == 0 {
+	defs := maps.Clone(c.definitions)
+
+	// Remove the root type from the definitions. No need to include it in the
+	// definitions.
+	delete(defs, typePath(c.root))
+
+	if len(defs) == 0 {
 		return nil
 	}
 
 	res := make(map[string]any)
-	for k, v := range c.definitions {
+	for k, v := range defs {
 		parts := strings.Split(k, "/")
 		cur := res
 		for i, p := range parts {
@@ -72,47 +72,74 @@ func (c *constructor) nestedDefinitions() any {
 	return res
 }
 
-// TODO: Skip generating schema for interface fields.
+// FromType converts a reflect.Type to a jsonschema.Schema. Nodes in the final JSON
-func FromType(typ reflect.Type, fn func(s Schema) Schema) (Schema, error) {
+// schema are guaranteed to be one level deep, which is done using defining $defs
+// for every Go type and referring them using $ref in the corresponding node in
+// the JSON schema.
+//
+// fns is a list of transformation functions that will be applied to all $defs
+// in the schema.
+func FromType(typ reflect.Type, fns []func(typ reflect.Type, s Schema) Schema) (Schema, error) {
 	c := constructor{
 		definitions: make(map[string]Schema),
-		seen:        make(map[string]struct{}),
+		seen:        make(map[string]reflect.Type),
-		fn:          fn,
+		root:        typ,
 	}
 
 	err := c.walk(typ)
 	if err != nil {
-		return InvalidSchema, err
+		return Schema{}, err
+	}
+
+	for k, v := range c.definitions {
+		for _, fn := range fns {
+			c.definitions[k] = fn(c.seen[k], v)
+		}
 	}
 
 	res := c.definitions[typePath(typ)]
-	// No need to include the root type in the definitions.
+	res.Definitions = c.Definitions()
-	delete(c.definitions, typePath(typ))
-	res.Definitions = c.nestedDefinitions()
 	return res, nil
 }
 
+// typePath computes a unique string representation of the type. $ref in the generated
+// JSON schema will refer to this path. See TestTypePath for examples outputs.
 func typePath(typ reflect.Type) string {
 	// Pointers have a typ.Name() of "". Dereference them to get the underlying type.
 	for typ.Kind() == reflect.Ptr {
 		typ = typ.Elem()
 	}
 
-	// typ.Name() resolves to "" for any type.
 	if typ.Kind() == reflect.Interface {
 		return "interface"
 	}
 
-	// For built-in types, return the type name directly.
+	// Recursively call typePath, to handle slices of slices / maps.
-	if typ.PkgPath() == "" {
+	if typ.Kind() == reflect.Slice {
-		return typ.Name()
+		return path.Join("slice", typePath(typ.Elem()))
 	}
 
-	return strings.Join([]string{typ.PkgPath(), typ.Name()}, ".")
+	if typ.Kind() == reflect.Map {
+		if typ.Key().Kind() != reflect.String {
+			panic(fmt.Sprintf("found map with non-string key: %v", typ.Key()))
+		}
+
+		// Recursively call typePath, to handle maps of maps / slices.
+		return path.Join("map", typePath(typ.Elem()))
+	}
+
+	switch {
+	case typ.PkgPath() != "" && typ.Name() != "":
+		return typ.PkgPath() + "." + typ.Name()
+	case typ.Name() != "":
+		return typ.Name()
+	default:
+		panic("unexpected empty type name for type: " + typ.String())
+	}
 }
 
-// TODO: would a worked based model fit better here? Is this internal API not
+// Walk the Go type, generating $defs for every type encountered, and populating
-// the right fit?
+// the corresponding $ref in the JSON schema.
 func (c *constructor) walk(typ reflect.Type) error {
 	// Dereference pointers if necessary.
 	for typ.Kind() == reflect.Ptr {
@@ -121,10 +148,11 @@ func (c *constructor) walk(typ reflect.Type) error {
 
 	typPath := typePath(typ)
 
-	// Keep track of seen types to avoid infinite recursion.
+	// Return early if the type has already been seen, to avoid infinite recursion.
-	if _, ok := c.seen[typPath]; !ok {
+	if _, ok := c.seen[typPath]; ok {
-		c.seen[typPath] = struct{}{}
+		return nil
 	}
+	c.seen[typPath] = typ
 
 	// Return early directly if it's already been processed.
 	if _, ok := c.definitions[typPath]; ok {
@@ -134,7 +162,6 @@ func (c *constructor) walk(typ reflect.Type) error {
 	var s Schema
 	var err error
 
-	// TODO: Narrow / widen down the number of Go types handled here.
 	switch typ.Kind() {
 	case reflect.Struct:
 		s, err = c.fromTypeStruct(typ)
@@ -142,20 +169,20 @@ func (c *constructor) walk(typ reflect.Type) error {
 		s, err = c.fromTypeSlice(typ)
 	case reflect.Map:
 		s, err = c.fromTypeMap(typ)
-		// TODO: Should the primitive functions below be inlined?
 	case reflect.String:
 		s = Schema{Type: StringType}
 	case reflect.Bool:
 		s = Schema{Type: BooleanType}
-	// TODO: Add comment about reduced coverage of primitive Go types in the code paths here.
+	case reflect.Int, reflect.Int32, reflect.Int64:
-	case reflect.Int:
 		s = Schema{Type: IntegerType}
 	case reflect.Float32, reflect.Float64:
 		s = Schema{Type: NumberType}
 	case reflect.Interface:
-		// An interface value can never be serialized from text, and thus is explicitly
+		// Interface or any types are not serialized to JSON by the default JSON
-		// set to null and disallowed in the schema.
+		// unmarshaller (json.Unmarshal). They likely thus are parsed by the
-		s = Schema{Type: NullType}
+		// dynamic configuration tree and we should support arbitary values here.
+		// Eg: variables.default can be anything.
+		s = Schema{}
 	default:
 		return fmt.Errorf("unsupported type: %s", typ.Kind())
 	}
@@ -163,13 +190,7 @@ func (c *constructor) walk(typ reflect.Type) error {
 		return err
 	}
 
-	if c.fn != nil {
+	// Store the computed JSON schema for the type.
-		s = c.fn(s)
-	}
-
-	// Store definition for the type if it's part of a Go package and not a built-in type.
-	// TODO: Apply transformation at the end, to all definitions instead of
-	// during recursive traversal?
 	c.definitions[typPath] = s
 	return nil
 }
@@ -206,20 +227,15 @@ func getStructFields(typ reflect.Type) []reflect.StructField {
 	return fields
 }
 
-// TODO: get rid of the errors here and panic instead?
 func (c *constructor) fromTypeStruct(typ reflect.Type) (Schema, error) {
 	if typ.Kind() != reflect.Struct {
-		return InvalidSchema, fmt.Errorf("expected struct, got %s", typ.Kind())
+		return Schema{}, fmt.Errorf("expected struct, got %s", typ.Kind())
 	}
 
 	res := Schema{
-		Type: ObjectType,
+		Type:                 ObjectType,
-
+		Properties:           make(map[string]*Schema),
-		Properties: make(map[string]*Schema),
+		Required:             []string{},
-
-		// TODO: Confirm that empty arrays are not serialized.
-		Required: []string{},
-
 		AdditionalProperties: false,
 	}
 
@@ -240,6 +256,7 @@ func (c *constructor) fromTypeStruct(typ reflect.Type) (Schema, error) {
 		if jsonTags[0] == "" || jsonTags[0] == "-" || !structField.IsExported() {
 			continue
 		}
+
 		// "omitempty" tags in the Go SDK structs represent fields that not are
 		// required to be present in the API payload. Thus its absence in the
 		// tags list indicates that the field is required.
@@ -247,19 +264,16 @@ func (c *constructor) fromTypeStruct(typ reflect.Type) (Schema, error) {
 			res.Required = append(res.Required, jsonTags[0])
 		}
 
+		// Walk the fields of the struct.
 		typPath := typePath(structField.Type)
-		// Only walk if the type has not been seen yet.
+		err := c.walk(structField.Type)
-		if _, ok := c.seen[typPath]; !ok {
+		if err != nil {
-			// Trigger call to fromType, to recursively generate definitions for
+			return Schema{}, err
-			// the struct field.
-			err := c.walk(structField.Type)
-			if err != nil {
-				return InvalidSchema, err
-			}
 		}
 
+		// For every property in the struct, add a $ref to the corresponding
+		// $defs block.
 		refPath := path.Join("#/$defs", typPath)
-		// For non-built-in types, refer to the definition.
 		res.Properties[jsonTags[0]] = &Schema{
 			Reference: &refPath,
 		}
@@ -268,11 +282,9 @@ func (c *constructor) fromTypeStruct(typ reflect.Type) (Schema, error) {
 	return res, nil
 }
 
-// TODO: Add comments explaining the translation between struct, map, slice and
-// the JSON schema representation.
 func (c *constructor) fromTypeSlice(typ reflect.Type) (Schema, error) {
 	if typ.Kind() != reflect.Slice {
-		return InvalidSchema, fmt.Errorf("expected slice, got %s", typ.Kind())
+		return Schema{}, fmt.Errorf("expected slice, got %s", typ.Kind())
 	}
 
 	res := Schema{
@@ -280,19 +292,16 @@ func (c *constructor) fromTypeSlice(typ reflect.Type) (Schema, error) {
 	}
 
 	typPath := typePath(typ.Elem())
-	// Only walk if the type has not been seen yet.
+
-	if _, ok := c.seen[typPath]; !ok {
+	// Walk the slice element type.
-		// Trigger call to fromType, to recursively generate definitions for
+	err := c.walk(typ.Elem())
-		// the slice element.
+	if err != nil {
-		err := c.walk(typ.Elem())
+		return Schema{}, err
-		if err != nil {
-			return InvalidSchema, err
-		}
 	}
 
 	refPath := path.Join("#/$defs", typPath)
 
-	// For non-built-in types, refer to the definition
+	// Add a $ref to the corresponding $defs block for the slice element type.
 	res.Items = &Schema{
 		Reference: &refPath,
 	}
@@ -301,11 +310,11 @@ func (c *constructor) fromTypeSlice(typ reflect.Type) (Schema, error) {
 
 func (c *constructor) fromTypeMap(typ reflect.Type) (Schema, error) {
 	if typ.Kind() != reflect.Map {
-		return InvalidSchema, fmt.Errorf("expected map, got %s", typ.Kind())
+		return Schema{}, fmt.Errorf("expected map, got %s", typ.Kind())
 	}
 
 	if typ.Key().Kind() != reflect.String {
-		return InvalidSchema, fmt.Errorf("found map with non-string key: %v", typ.Key())
+		return Schema{}, fmt.Errorf("found map with non-string key: %v", typ.Key())
 	}
 
 	res := Schema{
@@ -313,19 +322,16 @@ func (c *constructor) fromTypeMap(typ reflect.Type) (Schema, error) {
 	}
 
 	typPath := typePath(typ.Elem())
-	// Only walk if the type has not been seen yet.
+
-	if _, ok := c.seen[typPath]; !ok {
+	// Walk the map value type.
-		// Trigger call to fromType, to recursively generate definitions for
+	err := c.walk(typ.Elem())
-		// the map value.
+	if err != nil {
-		err := c.walk(typ.Elem())
+		return Schema{}, err
-		if err != nil {
-			return InvalidSchema, err
-		}
 	}
 
 	refPath := path.Join("#/$defs", typPath)
 
-	// For non-built-in types, refer to the definition
+	// Add a $ref to the corresponding $defs block for the map value type.
 	res.AdditionalProperties = &Schema{
 		Reference: &refPath,
 	}

libs/jsonschema/from_type_test.go

@@ -67,9 +67,7 @@ func TestFromTypeBasic(t *testing.T) {
 			expected: Schema{
 				Type: "object",
 				Definitions: map[string]any{
-					"interface": Schema{
+					"interface": Schema{},
-						Type: "null",
-					},
 					"string": Schema{
 						Type: "string",
 					},
@@ -160,6 +158,8 @@ func TestGetStructFields(t *testing.T) {
 	assert.Equal(t, "B", fields[2].Name)
 }
 
+// TODO: Add other case coverage for all the tests below
+
 func TestFromTypeNested(t *testing.T) {
 	type Inner struct {
 		S string `json:"s"`
@@ -222,7 +222,7 @@ func TestFromTypeNested(t *testing.T) {
 		},
 		{
 			name: "struct as a map value",
-			typ:  reflect.TypeOf(map[string]Inner{}),
+			typ:  reflect.TypeOf(map[string]*Inner{}),
 			expected: Schema{
 				Type:        "object",
 				Definitions: expectedDefinitions,
@@ -252,7 +252,6 @@ func TestFromTypeNested(t *testing.T) {
 	}
 }
 
-// TODO: Call out in the PR description that recursive Go types are supported.
 func TestFromTypeRecursive(t *testing.T) {
 	fooRef := "#/$defs/github.com/databricks/cli/libs/jsonschema/test_types.Foo"
 	barRef := "#/$defs/github.com/databricks/cli/libs/jsonschema/test_types.Bar"
@@ -353,8 +352,76 @@ func TestFromTypeSelfReferential(t *testing.T) {
 	assert.Equal(t, expected, s)
 }
 
+// TODO: Add coverage for all errors returned by FromType.
 func TestFromTypeError(t *testing.T) {
 	type mapOfInts map[int]int
-	_, err := FromType(reflect.TypeOf(mapOfInts{}), nil)
+
-	assert.EqualError(t, err, "found map with non-string key: int")
+	assert.PanicsWithValue(t, "found map with non-string key: int", func() {
+		FromType(reflect.TypeOf(mapOfInts{}), nil)
+	})
+}
+
+// TODO: Add test that the fn argument ot from_type works as expected.
+
+func TestTypePath(t *testing.T) {
+	type myStruct struct{}
+
+	tcases := []struct {
+		typ  reflect.Type
+		path string
+	}{
+		{
+			typ:  reflect.TypeOf(""),
+			path: "string",
+		},
+		{
+			typ:  reflect.TypeOf(int(0)),
+			path: "int",
+		},
+		{
+			typ:  reflect.TypeOf(true),
+			path: "bool",
+		},
+		{
+			typ:  reflect.TypeOf(float64(0)),
+			path: "float64",
+		},
+		{
+			typ:  reflect.TypeOf(myStruct{}),
+			path: "github.com/databricks/cli/libs/jsonschema.myStruct",
+		},
+		{
+			typ:  reflect.TypeOf([]int{}),
+			path: "slice/int",
+		},
+		{
+			typ:  reflect.TypeOf(map[string]int{}),
+			path: "map/int",
+		},
+		{
+			typ:  reflect.TypeOf([]myStruct{}),
+			path: "slice/github.com/databricks/cli/libs/jsonschema.myStruct",
+		},
+		{
+			typ:  reflect.TypeOf([][]map[string]map[string]myStruct{}),
+			path: "slice/slice/map/map/github.com/databricks/cli/libs/jsonschema.myStruct",
+		},
+		{
+			typ:  reflect.TypeOf(map[string]myStruct{}),
+			path: "map/github.com/databricks/cli/libs/jsonschema.myStruct",
+		},
+	}
+
+	// TODO: support arbitary depth of maps and slices. Also add validation
+	// in this function that non-string keys are not allowed.
+	for _, tc := range tcases {
+		t.Run(tc.typ.String(), func(t *testing.T) {
+			assert.Equal(t, tc.path, typePath(tc.typ))
+		})
+	}
+
+	// Maps with non-string keys should panic.
+	assert.PanicsWithValue(t, "found map with non-string key: int", func() {
+		typePath(reflect.TypeOf(map[int]int{}))
+	})
 }