fix(output): don't output empty files if there is nothing to write

Signed-off-by: Jeff Davis <[email protected]>
vmware-tanzu-labs · Jun 1, 2021 · 3e69cb8 · 3e69cb8
1 parent 257003f
commit 3e69cb8
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Showing 3 changed files with 106 additions and 87 deletions.
diff --git a/internal/instructions/config.go b/internal/instructions/config.go
@@ -4,8 +4,14 @@
 package instructions
 
 import (
+	"bytes"
+	"fmt"
+	"os"
+	"path"
+
 	"github.com/op/go-logging"
 	"github.com/vmware-tanzu-labs/yaml-overlay-tool/internal/actions"
+	"gopkg.in/yaml.v3"
 )
 
 // Config contains configuration options used with instruction files.
@@ -19,3 +25,102 @@ type Config struct {
 	Styles           actions.Styles
 	Values           []string
 }
+
+// doPostProcessing renders a document and outputs it to the location specified in config.
+func (cfg *Config) doPostProcessing(yf *YamlFile) error {
+	var o *os.File
+
+	var err error
+
+	output, err := cfg.encodeNodes(yf.Nodes)
+	if err != nil {
+		return fmt.Errorf("unable to marshal final document %s, error: %w", yf.Path, err)
+	}
+
+	if output.Len() == 0 {
+		log.Debugf("File %s was omitted from output", yf.Path)
+
+		return nil
+	}
+
+	if cfg.StdOut {
+		o = os.Stdout
+	} else {
+		log.Debugf("Final: >>>\n%s\n", output)
+		o, err = cfg.openOutputFile(yf)
+		if err != nil {
+			return err
+		}
+
+		defer CloseFile(o)
+	}
+
+	if _, err = output.WriteTo(o); err != nil {
+		return fmt.Errorf("failed to %w", err)
+	}
+
+	output.Reset()
+
+	return nil
+}
+
+// openOutputFile opens or creates a file for outputing results.
+func (cfg *Config) openOutputFile(yf *YamlFile) (*os.File, error) {
+	fileName := path.Join(cfg.OutputDir, yf.OutputPath)
+	dirName := path.Dir(fileName)
+
+	if _, err := os.Stat(dirName); os.IsNotExist(err) {
+		if err := os.MkdirAll(dirName, 0755); err != nil {
+			return nil, fmt.Errorf("failed to create output directory %s, %w", dirName, err)
+		}
+	}
+
+	file, err := os.OpenFile(fileName, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0644)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create/open file %s: %w", fileName, err)
+	}
+
+	os.Stdout.WriteString(fileName + "\n")
+
+	return file, nil
+}
+
+// encodeNodes processes each node given and encodes them into a single buffer for output.
+func (cfg *Config) encodeNodes(nodes []*yaml.Node) (*bytes.Buffer, error) {
+	var fileWritten bool
+
+	output := new(bytes.Buffer)
+
+	ye := yaml.NewEncoder(output)
+
+	defer func() {
+		if fileWritten {
+			if err := ye.Close(); err != nil {
+				log.Criticalf("error closing encoder, %s", err)
+			}
+		}
+	}()
+
+	ye.SetIndent(cfg.Indent)
+
+	for i, node := range nodes {
+		if len(node.Content) == 0 {
+			continue
+		}
+
+		if i == 0 {
+			output.WriteString("---\n")
+		}
+
+		actions.SetStyle(cfg.Styles, node)
+
+		err := ye.Encode(node)
+		if err != nil {
+			return nil, fmt.Errorf("%w", err)
+		}
+
+		fileWritten = true
+	}
+
+	return output, nil
+}
diff --git a/internal/instructions/execute.go b/internal/instructions/execute.go
@@ -81,7 +81,7 @@ func Execute(cfg *Config) error {
 // saving to file or displaying to screen.
 func PostProcessHandler(cfg *Config, pChan <-chan *YamlFile) error {
 	for yf := range pChan {
-		if err := yf.doPostProcessing(cfg); err != nil {
+		if err := cfg.doPostProcessing(yf); err != nil {
 			return err
 		}
 	}

diff --git a/internal/instructions/yamlfile.go b/internal/instructions/yamlfile.go
@@ -4,14 +4,12 @@
 package instructions
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"io"
 	"os"
 	"path"
 
-	"github.com/vmware-tanzu-labs/yaml-overlay-tool/internal/actions"
 	"github.com/vmware-tanzu-labs/yaml-overlay-tool/internal/overlays"
 	"gopkg.in/yaml.v3"
 )
@@ -59,69 +57,6 @@ func (yf *YamlFile) queueOverlays(stream *overlays.WorkStream) {
 	stream.CloseStream()
 }
 
-// doPostProcessing renders a document and outputs it to the location specified in config.
-func (yf *YamlFile) doPostProcessing(cfg *Config) error {
-	var o *os.File
-
-	var err error
-
-	var fileWritten bool
-
-	output := new(bytes.Buffer)
-
-	ye := yaml.NewEncoder(output)
-
-	defer func() {
-		if fileWritten {
-			if err = ye.Close(); err != nil {
-				log.Criticalf("error closing encoder, %s", err)
-			}
-		}
-	}()
-
-	ye.SetIndent(cfg.Indent)
-
-	for i, node := range yf.Nodes {
-		if len(node.Content) == 0 {
-			continue
-		}
-
-		if i == 0 {
-			output.WriteString("---\n")
-		}
-
-		actions.SetStyle(cfg.Styles, node)
-
-		err = ye.Encode(node)
-		if err != nil {
-			return fmt.Errorf("unable to marshal final document %s, error: %w", yf.Path, err)
-		}
-
-		fileWritten = true
-	}
-
-	// added so we can quickly see the results of the run
-	if cfg.StdOut {
-		o = os.Stdout
-	} else {
-		log.Debugf("Final: >>>\n%s\n", output)
-		o, err = yf.OpenOutputFile(cfg)
-		if err != nil {
-			return err
-		}
-
-		defer CloseFile(o)
-	}
-
-	if _, err = output.WriteTo(o); err != nil {
-		return fmt.Errorf("failed to %w", err)
-	}
-
-	output.Reset()
-
-	return nil
-}
-
 func (yfs *YamlFiles) UnmarshalYAML(value *yaml.Node) error {
 	var yft []*YamlFile
 
@@ -147,27 +82,6 @@ func (yfs *YamlFiles) UnmarshalYAML(value *yaml.Node) error {
 	return nil
 }
 
-// OpenOutputFile opens or creates a file for outputing results.
-func (yf *YamlFile) OpenOutputFile(o *Config) (*os.File, error) {
-	fileName := path.Join(o.OutputDir, yf.OutputPath)
-	dirName := path.Dir(fileName)
-
-	if _, err := os.Stat(dirName); os.IsNotExist(err) {
-		if err := os.MkdirAll(dirName, 0755); err != nil {
-			return nil, fmt.Errorf("failed to create output directory %s, %w", dirName, err)
-		}
-	}
-
-	file, err := os.OpenFile(fileName, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0644)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create/open file %s: %w", fileName, err)
-	}
-
-	os.Stdout.WriteString(fileName + "\n")
-
-	return file, nil
-}
-
 func (yf *YamlFile) readYamlFile() error {
 	reader, err := ReadStream(yf.Path)
 	if err != nil {