Fix lint errors

Signed-off-by: Frank Mueller <mail@themue.dev>

etc/etc.go

@@ -203,7 +203,10 @@ func (e *Etc) Split(path string) (*Etc, error) {
 	if err != nil {
 		return nil, failure.Annotate(err, "cannot split configuration")
 	}
-	values.At(fullPath[len(fullPath)-1:]...).SetKey("etc")
+	_, err = values.At(fullPath[len(fullPath)-1:]...).SetKey("etc")
+	if err != nil {
+		return nil, failure.Annotate(err, "cannot split configuration")
+	}
 	es := &Etc{
 		values: values,
 	}
@@ -257,21 +260,39 @@ func (e *Etc) Write(target io.Writer, prettyPrint bool) error {
 		doDepth := len(ks)
 		tag := ks[doDepth-1]
 		for i := depth; i > doDepth; i-- {
-			builder.EndTagNode()
+			if err := builder.EndTagNode(); err != nil {
+				return err
+			}
 		}
 		switch {
 		case doDepth > depth:
-			builder.BeginTagNode(tag)
-			builder.TextNode(v)
+			if err := builder.BeginTagNode(tag); err != nil {
+				return err
+			}
+			if err := builder.TextNode(v); err != nil {
+				return err
+			}
 			depth = doDepth
 		case doDepth == depth:
-			builder.EndTagNode()
-			builder.BeginTagNode(tag)
-			builder.TextNode(v)
+			if err := builder.EndTagNode(); err != nil {
+				return err
+			}
+			if err := builder.BeginTagNode(tag); err != nil {
+				return err
+			}
+			if err := builder.TextNode(v); err != nil {
+				return err
+			}
 		case doDepth < depth:
-			builder.EndTagNode()
-			builder.BeginTagNode(tag)
-			builder.TextNode(v)
+			if err := builder.EndTagNode(); err != nil {
+				return err
+			}
+			if err := builder.BeginTagNode(tag); err != nil {
+				return err
+			}
+			if err := builder.TextNode(v); err != nil {
+				return err
+			}
 			depth = doDepth
 		}
 		return nil
@@ -280,7 +301,9 @@ func (e *Etc) Write(target io.Writer, prettyPrint bool) error {
 		return err
 	}
 	for i := depth; i > 0; i-- {
-		builder.EndTagNode()
+		if err := builder.EndTagNode(); err != nil {
+			return err
+		}
 	}
 	root, err := builder.Root()
 	if err != nil {

gjp/gjp_test.go

@@ -44,7 +44,8 @@ func TestClear(t *testing.T) {
 	doc, err := gjp.Parse(bs, "/")
 	assert.Nil(err)
 	doc.Clear()
-	doc.SetValueAt("/", "foo")
+	err = doc.SetValueAt("/", "foo")
+	assert.NoError(err)
 	foo := doc.ValueAt("/").AsString("<undefined>")
 	assert.Equal(foo, "foo")
 }

go.mod

@@ -4,6 +4,7 @@ go 1.13
 
 require (
 	tideland.dev/go/audit v0.3.0
+	tideland.dev/go/dsa v0.3.0
 	tideland.dev/go/together v0.0.0-20200110213028-8f143e2737a6
 	tideland.dev/go/trace v0.0.0-20200110203012-77bd5be58e01
 )

go.sum

@@ -1,6 +1,8 @@
 tideland.dev/go v0.2.0 h1:JC/dwuqqn8NfU2jTNytDCjzbUTsWFGj1V2XfYJn0MKI=
 tideland.dev/go/audit v0.3.0 h1:zUEjdr279z7OE+iFsqz8xQm4KrLRxARmUSg5TzlO2RY=
 tideland.dev/go/audit v0.3.0/go.mod h1:iVQWp3A7czp2I4eH9nHERMMqljQRuwqTKuEzxoj9crI=
+tideland.dev/go/dsa v0.3.0 h1:zIZDlIvVgzspyypZZfJsZqDQMVFAPEoBGbrR2xy942A=
+tideland.dev/go/dsa v0.3.0/go.mod h1:8wQ77lLGRU3IRovPKxjHDBpj48u/QyYR5L3YWQFrwn0=
 tideland.dev/go/together v0.0.0-20200110213028-8f143e2737a6 h1:RcwIrnqp20h2CJUVIJj3oHgDbUajmXvR5b4u9yVc3hg=
 tideland.dev/go/together v0.0.0-20200110213028-8f143e2737a6/go.mod h1:g+TjCwnKorfsYdJk0XwGYeP3mxSvF1MbnWoQpKk3Y+U=
 tideland.dev/go/trace v0.0.0-20200110203012-77bd5be58e01 h1:KKlJTuzV2lnWnnI2dY6loIO1iHxnL9+akHnXrTVY8wc=

scroller/scroller.go

@@ -274,8 +274,8 @@ SeekLoop:
 		buffer = buffer[0:end]
 	}
 	// Final positioning.
-	s.source.Seek(seekPos, io.SeekStart)
-	return nil
+	_, err = s.source.Seek(seekPos, io.SeekStart)
+	return err
 }
 
 // readLine reads the next valid line from the reader, even if it is
@@ -302,7 +302,9 @@ func (s *Scroller) readLine() ([]byte, error) {
 		case io.EOF:
 			// Reached EOF without a delimiter,
 			// so step back for next time.
-			s.source.Seek(-int64(len(line)), io.SeekCurrent)
+			if _, serr := s.source.Seek(-int64(len(line)), io.SeekCurrent); serr != nil {
+				return nil, serr
+			}
 			return nil, err
 		default:
 			return nil, err

scroller/scroller_test.go

@@ -147,7 +147,7 @@ var tests = []struct {
 	injector: func(s *scroller.Scroller, rs *readSeeker) func([]string) {
 		return func(lines []string) {
 			if len(lines) == 25 {
-				s.Stop()
+				_ = s.Stop()
 			}
 		}
 	},
@@ -377,7 +377,8 @@ func newReceiver(assert *asserts.Asserts, data []string) *receiver {
 
 func (r *receiver) autoClose(scroller *scroller.Scroller) {
 	go func() {
-		scroller.Wait()
+		// Error of Wait() can be ignored here. Will be tested later.
+		_ = scroller.Wait()
 		r.writer.Close()
 	}()
 }

sml/nodes.go

@@ -104,7 +104,9 @@ func (tn *tagNode) ProcessWith(p Processor) error {
 func (tn *tagNode) String() string {
 	var buf bytes.Buffer
 	context := NewWriterContext(NewStandardSMLWriter(), &buf, true, "\t")
-	WriteSML(tn, context)
+	if err := WriteSML(tn, context); err != nil {
+		panic(err)
+	}
 	return buf.String()
 }
 

sml/reader.go

@@ -136,7 +136,9 @@ func (mr *mlReader) readTagChildren() error {
 			}
 		default:
 			mr.index--
-			mr.reader.UnreadRune()
+			if err = mr.reader.UnreadRune(); err != nil {
+				return err
+			}
 			if err = mr.readTextNode(); err != nil {
 				return err
 			}
@@ -155,7 +157,9 @@ func (mr *mlReader) readBracedContent() error {
 		return failure.New("unexpected end of file while reading a tag or raw node")
 	case rc == rcTag:
 		mr.index--
-		mr.reader.UnreadRune()
+		if err = mr.reader.UnreadRune(); err != nil {
+			return err
+		}
 		return mr.readTagNode()
 	case rc == rcExclamation:
 		return mr.readRawNode()
@@ -233,7 +237,9 @@ func (mr *mlReader) readTextNode() error {
 			return failure.New("unexpected end of file while reading a text node")
 		case rc == rcOpen || rc == rcClose:
 			mr.index--
-			mr.reader.UnreadRune()
+			if err = mr.reader.UnreadRune(); err != nil {
+				return err
+			}
 			return mr.builder.TextNode(buf.String())
 		case rc == rcEscape:
 			r, rc, err = mr.readRune()

sml/sml_test.go

@@ -80,8 +80,8 @@ func TestWriterProcessing(t *testing.T) {
 	ctxA := sml.NewWriterContext(sml.NewStandardSMLWriter(), bufA, true, "    ")
 	ctxB := sml.NewWriterContext(sml.NewStandardSMLWriter(), bufB, false, "")
 
-	sml.WriteSML(root, ctxA)
-	sml.WriteSML(root, ctxB)
+	assert.NoError(sml.WriteSML(root, ctxA))
+	assert.NoError(sml.WriteSML(root, ctxB))
 
 	assert.Logf("===== WITH INDENT =====")
 	assert.Logf(bufA.String())
@@ -107,7 +107,7 @@ func TestPositiveNodeReading(t *testing.T) {
 
 	buf := bytes.NewBufferString("")
 	ctx := sml.NewWriterContext(sml.NewStandardSMLWriter(), buf, true, "    ")
-	sml.WriteSML(root, ctx)
+	assert.NoError(sml.WriteSML(root, ctx))
 
 	assert.Logf("===== PARSED SML =====")
 	assert.Logf(buf.String())
@@ -172,8 +172,8 @@ for foo := 0; foo < 42; foo++ {
 
 	buf := bytes.NewBufferString("")
 	ctx := sml.NewWriterContext(sml.NewXMLWriter("pre"), buf, true, "    ")
-	ctx.Register("li", newLIWriter())
-	sml.WriteSML(root, ctx)
+	assert.NoError(ctx.Register("li", newLIWriter()))
+	assert.NoError(sml.WriteSML(root, ctx))
 
 	assert.Logf("===== XML =====")
 	assert.Logf(buf.String())
@@ -186,33 +186,34 @@ for foo := 0; foo < 42; foo++ {
 
 // Create a node structure.
 func createNodeStructure(assert *asserts.Asserts) sml.Node {
+	check := assert.NoError
 	builder := sml.NewNodeBuilder()
 
-	builder.BeginTagNode("root")
+	check(builder.BeginTagNode("root"))
 
-	builder.TextNode("Text A")
-	builder.TextNode("Text B")
-	builder.CommentNode("A first comment.")
+	check(builder.TextNode("Text A"))
+	check(builder.TextNode("Text B"))
+	check(builder.CommentNode("A first comment."))
 
-	builder.BeginTagNode("sub-a:1st:important")
-	builder.TextNode("Text A.A")
-	builder.CommentNode("A second comment.")
-	builder.EndTagNode()
+	check(builder.BeginTagNode("sub-a:1st:important"))
+	check(builder.TextNode("Text A.A"))
+	check(builder.CommentNode("A second comment."))
+	check(builder.EndTagNode())
 
-	builder.BeginTagNode("sub-b:2nd")
-	builder.TextNode("Text B.A")
-	builder.BeginTagNode("text")
-	builder.TextNode("Any text with the special characters {, }, and ^.")
-	builder.EndTagNode()
-	builder.EndTagNode()
+	check(builder.BeginTagNode("sub-b:2nd"))
+	check(builder.TextNode("Text B.A"))
+	check(builder.BeginTagNode("text"))
+	check(builder.TextNode("Any text with the special characters {, }, and ^."))
+	check(builder.EndTagNode())
+	check(builder.EndTagNode())
 
-	builder.BeginTagNode("sub-c")
-	builder.TextNode("Before raw.")
-	builder.RawNode("func Test(i int) { println(i) }")
-	builder.TextNode("After raw.")
-	builder.EndTagNode()
+	check(builder.BeginTagNode("sub-c"))
+	check(builder.TextNode("Before raw."))
+	check(builder.RawNode("func Test(i int) { println(i) }"))
+	check(builder.TextNode("After raw."))
+	check(builder.EndTagNode())
 
-	builder.EndTagNode()
+	check(builder.EndTagNode())
 
 	root, err := builder.Root()
 	assert.Nil(err)

sml/writer.go

@@ -179,17 +179,23 @@ func (w *mlWriter) activePlugin() WriterProcessor {
 func (w *mlWriter) writeIndent(open bool) {
 	if w.context.prettyPrint {
 		for i := 0; i < w.indent; i++ {
-			w.context.Writef(w.context.indentStr)
+			if err := w.context.Writef(w.context.indentStr); err != nil {
+				panic(err)
+			}
 		}
 	} else if open {
-		w.context.Writef(" ")
+		if err := w.context.Writef(" "); err != nil {
+			panic(err)
+		}
 	}
 }
 
 // writeNewline writes a newline if wanted.
 func (w *mlWriter) writeNewline() {
 	if w.context.prettyPrint {
-		w.context.Writef("\n")
+		if err := w.context.Writef("\n"); err != nil {
+			panic(err)
+		}
 	}
 }
 
@@ -277,12 +283,18 @@ func (w *xmlWriter) SetContext(ctx *WriterContext) {
 
 // OpenTag writes the opening of a tag.
 func (w *xmlWriter) OpenTag(tag []string) error {
-	w.context.Writef("<%s", tag[0])
+	if err := w.context.Writef("<%s", tag[0]); err != nil {
+		return err
+	}
 	if len(tag) > 1 {
-		w.context.Writef(" id=%q", tag[1])
+		if err := w.context.Writef(" id=%q", tag[1]); err != nil {
+			return err
+		}
 	}
 	if len(tag) > 2 {
-		w.context.Writef(" class=%q", tag[2])
+		if err := w.context.Writef(" class=%q", tag[2]); err != nil {
+			return err
+		}
 	}
 	return w.context.Writef(">")
 }