add missing error handling

Signed-off-by: Jakub Sokołowski <[email protected]>

Author: jakubgs

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bufio"
 	"flag"
-	"fmt"
 	"log"
 	"os"
 	"strings"
@@ -41,8 +40,7 @@ You can provide your own list using the -reposFile flag.
 func flagsInit() {
 	defaultUsage := flag.Usage
 	flag.Usage = func() {
-		fmt.Fprintf(os.Stderr, // TODO unhandled error
-			strings.Trim(helpMessage, "\t "),
+		l.Printf(strings.Trim(helpMessage, "\t "),
 			strings.Join(fetcher.DefaultRepos, "\n"))
 		defaultUsage()
 	}
@@ -92,7 +90,7 @@ func main() {
 	for scanner.Scan() {
 		dep, err := pom.DependencyFromString(scanner.Text())
 		if err != nil {
-			l.Printf("failed to parse input: %s", err)
+			l.Println("failed to parse input:", err)
 			continue
 		}
 		/* The threads print found URLs into STDOUT. */
@@ -101,7 +99,8 @@ func main() {
 
 	/* Reading from STDIN might fail. */
 	if err := scanner.Err(); err != nil {
-		l.Printf("error:", err) // TODO unhandled error
+		l.Println("stdin read error:", err)
+		os.Exit(1)
 	}
 
 	/* Each FindUrls() call can spawn more recursive FindUrls() routines.

pom/metadata.go

@@ -21,13 +21,17 @@ type Metadata struct {
 }
 
 /* For reading Metadata from downloaded XML file. */
-func MetadataFromReader(reader io.ReadCloser) (*Metadata, error) {
-	defer reader.Close() // TODO unhandled error
+func MetadataFromReader(reader io.ReadCloser) (meta *Metadata, err error) {
+	defer func() {
+		cerr := reader.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
 	decoder := xml.NewDecoder(reader)
 	decoder.CharsetReader = charset.NewReaderLabel
-	var meta Metadata
-	err := decoder.Decode(&meta)
-	return &meta, err
+	err = decoder.Decode(&meta)
+	return
 }
 
 /* There are multiple values that could indicate latest version. */

pom/project.go

@@ -20,13 +20,17 @@ type Project struct {
 }
 
 /* For reading Project from downloaded POM file. */
-func ProjectFromReader(reader io.ReadCloser) (*Project, error) {
-	defer reader.Close() // TODO unhandled error
+func ProjectFromReader(reader io.ReadCloser) (project *Project, err error) {
+	defer func() {
+		cerr := reader.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
 	decoder := xml.NewDecoder(reader)
 	decoder.CharsetReader = charset.NewReaderLabel
-	var project Project
-	err := decoder.Decode(&project)
-	return &project, err
+	err = decoder.Decode(&project)
+	return
 }
 
 /* Sometimes groupId is not specified in project */

read.go

@@ -6,15 +6,20 @@ import (
 )
 
 /* Just a helper for reading file with repo URLs. */
-func ReadFileToList(path string) ([]string, error) {
+func ReadFileToList(path string) (lines []string, err error) {
 	file, err := os.Open(path)
 	if err != nil {
 		return nil, err
 	}
-	defer file.Close() // TODO unhandled error
+
+	defer func() {
+		cerr := file.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
 
 	scanner := bufio.NewScanner(file)
-	var lines []string
 	for scanner.Scan() {
 		lines = append(lines, scanner.Text())
 	}