Implement isBool and add to list of supported functions

Also updates the changelog

Author: Lennart Elsen

.chloggen/27897-is-bool-converter.yaml

@@ -0,0 +1,26 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/ottl
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: The IsBool function is now available to OTTL
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [27897]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

pkg/ottl/expression.go

@@ -142,6 +142,43 @@ func (t TypeError) Error() string {
 	return string(t)
 }
 
+// BoolGetter is a Getter than must return a bool.
+type BoolGetter[K any] interface {
+	// Get retrieves a bool value.
+	Get(ctx context.Context, tCtx K) (bool, error)
+}
+
+// StandardBoolGetter is a basic implementation of BoolGetter
+type StandardBoolGetter[K any] struct {
+	Getter func(ctx context.Context, tCtx K) (interface{}, error)
+}
+
+const boolExpectMsg = "expected bool but got"
+
+// Get retrieves a bool value.
+// If the value is not a bool a new TypeError is returned.
+// If there is an error getting the value it will be returned.
+func (g StandardBoolGetter[K]) Get(ctx context.Context, tCtx K) (bool, error) {
+	val, err := g.Getter(ctx, tCtx)
+	if err != nil {
+		return false, fmt.Errorf("error getting value in %T: %w", g, err)
+	}
+	if val == nil {
+		return false, TypeError(boolExpectMsg + " nil")
+	}
+	switch v := val.(type) {
+	case bool:
+		return v, nil
+	case pcommon.Value:
+		if v.Type() == pcommon.ValueTypeBool {
+			return v.Bool(), nil
+		}
+		return false, TypeError(fmt.Sprintf("%s %v", boolExpectMsg, v.Type()))
+	default:
+		return false, TypeError(fmt.Sprintf("%s %T", boolExpectMsg, val))
+	}
+}
+
 // StringGetter is a Getter that must return a string.
 type StringGetter[K any] interface {
 	// Get retrieves a string value.

pkg/ottl/expression_test.go

@@ -614,6 +614,70 @@ func Test_exprGetter_Get_Invalid(t *testing.T) {
 	}
 }
 
+func Test_StandardBoolGetter(t *testing.T) {
+	tests := []struct {
+		name             string
+		getter           StandardBoolGetter[interface{}]
+		want             interface{}
+		valid            bool
+		expectedErrorMsg string
+	}{
+		{
+			name: "bool type",
+			getter: StandardBoolGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return true, nil
+				},
+			},
+			want:  true,
+			valid: true,
+		},
+		{
+			name: "ValueTypeBool type",
+			getter: StandardBoolGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return pcommon.NewValueBool(true), nil
+				},
+			},
+			want:  true,
+			valid: true,
+		},
+		{
+			name: "Incorrect type",
+			getter: StandardBoolGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return "str", nil
+				},
+			},
+			valid:            false,
+			expectedErrorMsg: boolExpectMsg + " string",
+		},
+		{
+			name: "nil",
+			getter: StandardBoolGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return nil, nil
+				},
+			},
+			valid:            false,
+			expectedErrorMsg: boolExpectMsg + " nil",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			val, err := tt.getter.Get(context.Background(), nil)
+			if tt.valid {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, val)
+			} else {
+				assert.IsType(t, TypeError(""), err)
+				assert.EqualError(t, err, tt.expectedErrorMsg)
+			}
+		})
+	}
+}
+
 func Test_StandardStringGetter(t *testing.T) {
 	tests := []struct {
 		name             string

pkg/ottl/ottlfuncs/func_is_bool.go

@@ -0,0 +1,46 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package ottlfuncs // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/ottlfuncs"
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+type IsBoolArguments[K any] struct {
+	Target ottl.BoolGetter[K]
+}
+
+func NewIsBoolFactory[K any]() ottl.Factory[K] {
+	return ottl.NewFactory("IsBool", &IsBoolArguments[K]{}, createIsBoolFunction[K])
+}
+
+func createIsBoolFunction[K any](_ ottl.FunctionContext, oArgs ottl.Arguments) (ottl.ExprFunc[K], error) {
+	args, ok := oArgs.(*IsBoolArguments[K])
+
+	if !ok {
+		return nil, fmt.Errorf("IsBoolFactory args must be of type *IsBoolArguments[K]")
+	}
+
+	return isBool(args.Target), nil
+}
+
+// nolint:errorlint
+func isBool[K any](target ottl.BoolGetter[K]) ottl.ExprFunc[K] {
+	return func(ctx context.Context, tCtx K) (interface{}, error) {
+		_, err := target.Get(ctx, tCtx)
+		
+		// Use type assertion because we don't want to check wrapped errors
+		switch err.(type) {
+		case ottl.TypeError:
+			return false, nil
+		case nil:
+			return true, nil
+		default:
+			return false, err
+		}
+	}
+}

pkg/ottl/ottlfuncs/func_is_bool_test.go

@@ -0,0 +1,74 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package ottlfuncs
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+func Test_IsBool(t *testing.T) {
+	tests := []struct {
+		name     string
+		value    interface{}
+		expected bool
+	}{
+		{
+			name:     "bool",
+			value:    true,
+			expected: true,
+		},
+		{
+			name:     "ValueTypeBool",
+			value:    pcommon.NewValueBool(true),
+			expected: true,
+		},
+		{
+			name:     "not bool",
+			value:    1,
+			expected: false,
+		},
+		{
+			name:     "ValueTypeSlice",
+			value:    pcommon.NewValueSlice(),
+			expected: false,
+		},
+		{
+			name:     "nil",
+			value:    nil,
+			expected: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			exprFunc := isBool[any](&ottl.StandardBoolGetter[any]{
+				Getter: func(context.Context, interface{}) (interface{}, error) {
+					return tt.value, nil
+				},
+			})
+			result, err := exprFunc(context.Background(), nil)
+			assert.NoError(t, err)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+// nolint:errorlint
+func Test_IsBool_Error(t *testing.T) {
+	exprFunc := isBool[any](&ottl.StandardBoolGetter[any]{
+		Getter: func(context.Context, interface{}) (interface{}, error) {
+			return nil, ottl.TypeError("")
+		},
+	})
+	result, err := exprFunc(context.Background(), nil)
+	assert.Equal(t, false, result)
+	assert.Error(t, err)
+	_, ok := err.(ottl.TypeError)
+	assert.False(t, ok)
+}

pkg/ottl/ottlfuncs/functions.go

@@ -42,6 +42,7 @@ func converters[K any]() []ottl.Factory[K] {
 		NewFnvFactory[K](),
 		NewHoursFactory[K](),
 		NewIntFactory[K](),
+		NewIsBoolFactory[K](),
 		NewIsMapFactory[K](),
 		NewIsMatchFactory[K](),
 		NewIsStringFactory[K](),