re-add ocb version command and unit tests

.chloggen/jackgopack4-re-add-ocb-version-number.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: cmd/builder
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: re-adds function to properly set and view version number of OpenTelemetry Collector Builder (ocb) binaries
+
+# One or more tracking issues or pull requests related to the change
+issues: [11208]
+
+# (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.
+subtext:
+
+# 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: []

cmd/builder/internal/command.go

@@ -116,7 +116,7 @@ configuration is provided, ocb will generate a default Collector.
 		return nil, err
 	}
 	// version of this binary
-	cmd.AddCommand(versionCommand())
+	cmd.AddCommand(versionCommand(binVersion))
 
 	return cmd, nil
 }

cmd/builder/internal/version.go

@@ -14,18 +14,34 @@ var (
 	version = ""
 )
 
-func init() {
-	// the second returned value is a boolean, which is true if the binaries are built with module support.
-	info, _ := debug.ReadBuildInfo()
-	version = info.Main.Version
+type debugReadBuildInfoFunc func() (info *debug.BuildInfo, ok bool)
+type binVersionFunc func(fn debugReadBuildInfoFunc) (string, error)
+
+// binVersion returns the version of the binary.
+// If the version is not set, it attempts to read the build information.
+// Returns an error if the build information cannot be read.
+func binVersion(fn debugReadBuildInfoFunc) (string, error) {
+	if version != "" {
+		return version, nil
+	}
+	info, ok := fn()
+	if !ok {
+		return "", fmt.Errorf("failed to read build info")
+	}
+	return info.Main.Version, nil
 }
 
-func versionCommand() *cobra.Command {
+func versionCommand(fn binVersionFunc) *cobra.Command {
+	var err error
 	return &cobra.Command{
 		Use:   "version",
 		Short: "Version of ocb",
 		Long:  "Prints the version of the ocb binary",
 		RunE: func(cmd *cobra.Command, _ []string) error {
+			version, err = fn(debug.ReadBuildInfo)
+			if err != nil {
+				return err
+			}
 			cmd.Println(fmt.Sprintf("%s version %s", cmd.Parent().Name(), version))
 			return nil
 		},

cmd/builder/internal/version_test.go

@@ -0,0 +1,123 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"runtime/debug"
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+// Mock debug.ReadBuildInfo function
+var readBuildInfo = debug.ReadBuildInfo
+
+func TestBinVersion(t *testing.T) {
+	// Test case: version is set
+	version = "v1.0.0"
+	v, err := binVersion(readBuildInfo)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if v != "v1.0.0" {
+		t.Fatalf("expected version 'v1.0.0', got %v", v)
+	}
+
+	// // Test case: version is not set, ReadBuildInfo returns valid info
+	version = ""
+	readBuildInfo = func() (*debug.BuildInfo, bool) {
+		return &debug.BuildInfo{
+			Main: debug.Module{
+				Version: "v2.0.0",
+			},
+		}, true
+	}
+	v, err = binVersion(readBuildInfo)
+	fmt.Printf("v: %v, err: %v", v, err)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if v != "v2.0.0" {
+		t.Fatalf("expected version 'v2.0.0', got %v", v)
+	}
+
+	// Test case: version is not set, ReadBuildInfo fails
+	readBuildInfo = func() (*debug.BuildInfo, bool) {
+		return nil, false
+	}
+	v, err = binVersion(readBuildInfo)
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	if v != "" {
+		t.Fatalf("expected empty version, got %v", v)
+	}
+}
+
+var validBinVersionFunc binVersionFunc = func(_ debugReadBuildInfoFunc) (string, error) {
+	return "v1.0.0", nil
+}
+
+var invalidBinVersionFunc binVersionFunc = func(_ debugReadBuildInfoFunc) (string, error) {
+	return "", fmt.Errorf("failed to get version")
+}
+
+func TestVersionCommand(t *testing.T) {
+	tests := []struct {
+		name           string
+		binVersion     binVersionFunc
+		expectedOutput string
+		expectedError  bool
+	}{
+		{
+			name:           "valid version",
+			binVersion:     validBinVersionFunc,
+			expectedOutput: "ocb version v1.0.0\n",
+			expectedError:  false,
+		},
+		{
+			name:           "error in binVersion",
+			binVersion:     invalidBinVersionFunc,
+			expectedOutput: "",
+			expectedError:  true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Set a mock parent command name
+			parentCmd := &cobra.Command{
+				Use: "ocb <command>",
+			}
+			// Create the command
+			var cmd = versionCommand(tt.binVersion)
+			parentCmd.AddCommand(cmd)
+			// Capture the output
+			output := bytes.NewBufferString("")
+			errOutput := bytes.NewBufferString("")
+			cmd.SetOut(output)
+			cmd.SetErr(errOutput)
+			// Create a new context with a fake value
+			type contextKey string
+			ctx := context.WithValue(context.Background(), contextKey("key"), "value")
+			// Set fake CLI arguments
+			fakeArgs := []string{"cmd", "version"}
+			os.Args = fakeArgs
+			// Execute the command
+			err := cmd.ExecuteContext(ctx)
+			// Check for expected error
+			if (err != nil) != tt.expectedError {
+				t.Fatalf("expected error: %v, got: %v", tt.expectedError, err)
+			}
+			// Check for expected output
+			if output.String() != tt.expectedOutput {
+				t.Fatalf("expected output: %v, got: %v", tt.expectedOutput, output.String())
+			}
+		})
+	}
+}