unhandled errors (#122)

* unhandled errors

* update defer() error handling

cmd/ion-go/main.go

@@ -38,7 +38,7 @@ func main() {
 		printHelp()
 
 	case "version", "--version", "-v":
-		printVersion()
+		err = printVersion()
 
 	case "process":
 		err = process(os.Args[2:])
@@ -71,26 +71,44 @@ func printHelp() {
 }
 
 // printVersion prints (in ion) the version info for this tool.
-func printVersion() {
+func printVersion() error {
 	w := ion.NewTextWriterOpts(os.Stdout, ion.TextWriterPretty)
 
-	w.BeginStruct()
+	if err := w.BeginStruct(); err != nil {
+		return err
+	}
 	{
-		w.FieldName("version")
-		w.WriteString(internal.GitCommit)
+		if err := w.FieldName("version"); err != nil {
+			return err
+		}
+		if err := w.WriteString(internal.GitCommit); err != nil {
+			return err
+		}
 
 		buildtime, err := ion.NewTimestampFromStr(internal.BuildTime, ion.TimestampPrecisionSecond, ion.TimezoneUTC)
 		if err == nil {
-			w.FieldName("build_time")
-			w.WriteTimestamp(buildtime)
+			if err := w.FieldName("build_time"); err != nil {
+				return err
+			}
+			if err := w.WriteTimestamp(buildtime); err != nil {
+				return err
+			}
 		} else {
-			w.FieldName("build_time")
-			w.WriteString("unknown-buildtime")
+			if err := w.FieldName("build_time"); err != nil {
+				return err
+			}
+			if err := w.WriteString("unknown-buildtime"); err != nil {
+				return err
+			}
 		}
 	}
-	w.EndStruct()
+	if err := w.EndStruct(); err != nil {
+		return err
+	}
 
 	if err := w.Finish(); err != nil {
 		panic(err)
 	}
+
+	return nil
 }

cmd/ion-go/process.go

@@ -98,12 +98,19 @@ func newProcessor(args []string) (*processor, error) {
 	return ret, nil
 }
 
-func (p *processor) run() error {
+func (p *processor) run() (deferredErr error) {
 	outf, err := OpenOutput(p.outf)
 	if err != nil {
 		return err
 	}
-	defer outf.Close()
+	defer func() {
+		closeError := outf.Close()
+		if err == nil {
+			deferredErr = closeError
+		} else {
+			deferredErr = err
+		}
+	}()
 
 	switch p.format {
 	case "", "pretty":
@@ -117,28 +124,44 @@ func (p *processor) run() error {
 	case "none":
 		p.out = NewNopWriter()
 	default:
-		return errors.New("unrecognized output format \"" + p.format + "\"")
+		err = errors.New("unrecognized output format \"" + p.format + "\"")
+		return err
 	}
 
 	errf, err := OpenError(p.errf)
 	if err != nil {
 		return err
 	}
-	defer errf.Close()
+	defer func() {
+		finishError := errf.Close()
+		if err == nil {
+			deferredErr = finishError
+		} else {
+			deferredErr = err
+		}
+	}()
 
 	p.err = NewErrorReport(errf)
-	defer p.err.Finish()
+	defer func() {
+		finishError := p.err.Finish()
+		if err == nil {
+			deferredErr = finishError
+		} else {
+			deferredErr = err
+		}
+	}()
 
 	if len(p.infs) == 0 {
 		p.processStdin()
 		return nil
 	}
 
-	if err := p.processFiles(); err != nil {
+	err = p.processFiles()
+	if err != nil {
 		return err
 	}
 
-	return nil
+	return err
 }
 
 func (p *processor) processStdin() {
@@ -165,12 +188,15 @@ func (p *processor) processFiles() error {
 	return nil
 }
 
-func (p *processor) processFile(in string) error {
+func (p *processor) processFile(in string) (err error) {
 	f, err := OpenInput(in)
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+
+	defer func() {
+		err = f.Close()
+	}()
 
 	p.loc = in
 	p.processReader(f)

cmd/ion-go/util.go

@@ -84,6 +84,6 @@ func (r *ErrorReport) Append(typ errortype, msg, loc string, idx int) {
 }
 
 // Finish finishes writing this report.
-func (r *ErrorReport) Finish() {
-	r.w.Finish()
+func (r *ErrorReport) Finish() error {
+	return r.w.Finish()
 }

ion/marshal.go

@@ -224,15 +224,21 @@ func (m *Encoder) encodeMap(v reflect.Value, hint Type) error {
 		return m.w.WriteNull()
 	}
 
-	m.w.BeginStruct()
+	err := m.w.BeginStruct()
+	if err != nil {
+		return err
+	}
 
 	keys := keysFor(v)
 	if m.opts&EncodeSortMaps != 0 {
 		sort.Slice(keys, func(i, j int) bool { return keys[i].s < keys[j].s })
 	}
 
 	for _, key := range keys {
-		m.w.FieldName(key.s)
+		err = m.w.FieldName(key.s)
+		if err != nil {
+			return err
+		}
 		value := v.MapIndex(key.v)
 		if err := m.encodeValue(value, hint); err != nil {
 			return err
@@ -295,9 +301,15 @@ func (m *Encoder) encodeBlob(v reflect.Value, hint Type) error {
 // EncodeArray encodes an array to the output writer as an Ion list (or sexp).
 func (m *Encoder) encodeArray(v reflect.Value, hint Type) error {
 	if hint == SexpType {
-		m.w.BeginSexp()
+		err := m.w.BeginSexp()
+		if err != nil {
+			return err
+		}
 	} else {
-		m.w.BeginList()
+		err := m.w.BeginList()
+		if err != nil {
+			return err
+		}
 	}
 
 	for i := 0; i < v.Len(); i++ {
@@ -352,7 +364,9 @@ FieldLoop:
 			continue
 		}
 
-		m.w.FieldName(f.name)
+		if err := m.w.FieldName(f.name); err != nil {
+			return err
+		}
 		if err := m.encodeValue(fv, f.hint); err != nil {
 			return err
 		}

ion/skipper.go

@@ -60,7 +60,10 @@ func (t *tokenizer) SkipDot() (bool, error) {
 		return false, nil
 	}
 
-	t.read()
+	_, err = t.read()
+	if err != nil {
+		return false, err
+	}
 	return true, nil
 }
 
@@ -869,7 +872,10 @@ func (t *tokenizer) skipDoubleColon() (bool, error) {
 	}
 
 	if cs[0] == ':' && cs[1] == ':' {
-		t.skipN(2)
+		err = t.skipN(2)
+		if err != nil {
+			return false, err
+		}
 		return true, nil
 	}
 

ion/symboltable.go

@@ -141,23 +141,43 @@ func (s *sst) FindByID(id uint64) (string, bool) {
 }
 
 func (s *sst) WriteTo(w Writer) error {
-	w.Annotation("$ion_shared_symbol_table")
-	w.BeginStruct()
+	if err := w.Annotation("$ion_shared_symbol_table"); err != nil {
+		return err
+	}
+	if err := w.BeginStruct(); err != nil {
+		return err
+	}
 	{
-		w.FieldName("name")
-		w.WriteString(s.name)
+		if err := w.FieldName("name"); err != nil {
+			return err
+		}
+		if err := w.WriteString(s.name); err != nil {
+			return err
+		}
 
-		w.FieldName("version")
-		w.WriteInt(int64(s.version))
+		if err := w.FieldName("version"); err != nil {
+			return err
+		}
+		if err := w.WriteInt(int64(s.version)); err != nil {
+			return err
+		}
 
-		w.FieldName("symbols")
-		w.BeginList()
+		if err := w.FieldName("symbols"); err != nil {
+			return err
+		}
+		if err := w.BeginList(); err != nil {
+			return err
+		}
 		{
 			for _, sym := range s.symbols {
-				w.WriteString(sym)
+				if err := w.WriteString(sym); err != nil {
+					return err
+				}
 			}
 		}
-		w.EndList()
+		if err := w.EndList(); err != nil {
+			return err
+		}
 	}
 	return w.EndStruct()
 }
@@ -348,38 +368,72 @@ func (t *lst) WriteTo(w Writer) error {
 		return nil
 	}
 
-	w.Annotation("$ion_symbol_table")
-	w.BeginStruct()
+	if err := w.Annotation("$ion_symbol_table"); err != nil {
+		return err
+	}
+	if err := w.BeginStruct(); err != nil {
+		return err
+	}
 
 	if len(t.imports) > 1 {
-		w.FieldName("imports")
-		w.BeginList()
+		if err := w.FieldName("imports"); err != nil {
+			return err
+		}
+		if err := w.BeginList(); err != nil {
+			return err
+		}
 		for i := 1; i < len(t.imports); i++ {
 			imp := t.imports[i]
-			w.BeginStruct()
+			if err := w.BeginStruct(); err != nil {
+				return err
+			}
 
-			w.FieldName("name")
-			w.WriteString(imp.Name())
+			if err := w.FieldName("name"); err != nil {
+				return err
+			}
+			if err := w.WriteString(imp.Name()); err != nil {
+				return err
+			}
 
-			w.FieldName("version")
-			w.WriteInt(int64(imp.Version()))
+			if err := w.FieldName("version"); err != nil {
+				return err
+			}
+			if err := w.WriteInt(int64(imp.Version())); err != nil {
+				return err
+			}
 
-			w.FieldName("max_id")
-			w.WriteUint(imp.MaxID())
+			if err := w.FieldName("max_id"); err != nil {
+				return err
+			}
+			if err := w.WriteUint(imp.MaxID()); err != nil {
+				return err
+			}
 
-			w.EndStruct()
+			if err := w.EndStruct(); err != nil {
+				return err
+			}
+		}
+		if err := w.EndList(); err != nil {
+			return err
 		}
-		w.EndList()
 	}
 
 	if len(t.symbols) > 0 {
-		w.FieldName("symbols")
+		if err := w.FieldName("symbols"); err != nil {
+			return err
+		}
 
-		w.BeginList()
+		if err := w.BeginList(); err != nil {
+			return err
+		}
 		for _, sym := range t.symbols {
-			w.WriteString(sym)
+			if err := w.WriteString(sym); err != nil {
+				return err
+			}
+		}
+		if err := w.EndList(); err != nil {
+			return err
 		}
-		w.EndList()
 	}
 
 	return w.EndStruct()

ion/textwriter.go

@@ -193,7 +193,10 @@ func (w *textWriter) WriteBlob(val []byte) error {
 	}
 
 	enc := base64.NewEncoder(base64.StdEncoding, w.out)
-	enc.Write(val)
+	_, err := enc.Write(val)
+	if err != nil {
+		return err
+	}
 	if w.err = enc.Close(); w.err != nil {
 		return w.err
 	}