pkg/md: Fix newlines around HTML blocks in FmtCodec.

Also:

- Show a trace of Op's when a test case fails.

- Don't loosify lists when comparing the HTML output of original and formatted.

pkg/md/fmt.go

@@ -95,6 +95,9 @@ func (c *FmtCodec) Do(op Op) {
 		c.write(delim)
 		c.write("\n")
 		c.code = false
+	case OpHTMLBlockStart:
+		c.ensureNewStanza()
+	case OpHTMLBlockEnd:
 	case OpParagraphStart:
 		c.ensureNewStanza()
 	case OpParagraphEnd:

pkg/md/fmt_test.go

@@ -20,8 +20,6 @@ func TestFmtPreservesHTMLRender(t *testing.T) {
 			switch tc.Example {
 			case 39, 40:
 				t.Skip("TODO escape sequence")
-			case 167, 280, 281, 282, 283, 284, 315:
-				t.Skip("TODO newline")
 			case 301, 302:
 				t.Skip("TODO change of list markers")
 			case 460, 462:
@@ -37,10 +35,12 @@ func TestFmtPreservesHTMLRender(t *testing.T) {
 func testFmtPreservesHTMLRender(t *testing.T, original string) {
 	formatted := render(original, &md.FmtCodec{})
 	formattedRender := render(formatted, &htmlCodec{})
-	originalRender := loosifyLists(render(original, &htmlCodec{}))
+	originalRender := render(original, &htmlCodec{})
 	if formattedRender != originalRender {
-		t.Errorf("original:\n%s\nformatted:\n%s\nHTML diff (-original +formatted):\n%s",
+		t.Errorf("original:\n%s\nformatted:\n%s\n"+
+			"HTML diff (-original +formatted):\n%sops diff (-original +formatted):\n%s",
 			hr+"\n"+original+hr, hr+"\n"+formatted+hr,
-			cmp.Diff(originalRender, formattedRender))
+			cmp.Diff(originalRender, formattedRender),
+			cmp.Diff(render(original, &md.OpTraceCodec{}), render(formatted, &md.OpTraceCodec{})))
 	}
 }

pkg/md/md.go

@@ -82,6 +82,8 @@ const (
 	OpHeadingEnd
 	OpCodeBlockStart
 	OpCodeBlockEnd
+	OpHTMLBlockStart
+	OpHTMLBlockEnd
 	OpParagraphStart
 	OpParagraphEnd
 
@@ -325,6 +327,9 @@ func (p *blockParser) parseIndentedCodeBlock(line string) {
 }
 
 func (p *blockParser) parseHTMLBlock(line string, closer func(string) bool) {
+	do(p.codec, OpHTMLBlockStart)
+	defer do(p.codec, OpHTMLBlockEnd)
+
 	doRawHTMLLine(p.codec, line)
 	if closer(line) {
 		return
@@ -349,6 +354,9 @@ func (p *blockParser) parseHTMLBlock(line string, closer func(string) bool) {
 }
 
 func (p *blockParser) parseBlankLineTerminatedHTMLBlock(line string) {
+	do(p.codec, OpHTMLBlockStart)
+	defer do(p.codec, OpHTMLBlockEnd)
+
 	doRawHTMLLine(p.codec, line)
 	for p.lines.more() {
 		line := p.lines.next()

pkg/md/optrace_test.go

@@ -0,0 +1,28 @@
+package md
+
+import (
+	"fmt"
+	"strings"
+)
+
+// OpTraceCodec is a Codec that records all the Op's passed to its Do method.
+type OpTraceCodec struct{ strings.Builder }
+
+func (c *OpTraceCodec) Do(op Op) {
+	if c.Len() > 0 {
+		c.WriteByte('\n')
+	}
+	c.WriteString(op.Type.String())
+	if op.Number != 0 {
+		fmt.Fprintf(c, " Number=%d", op.Number)
+	}
+	if op.Text != "" {
+		fmt.Fprintf(c, " Text=%q", op.Text)
+	}
+	if op.Dest != "" {
+		fmt.Fprintf(c, " Dest=%q", op.Dest)
+	}
+	if op.Alt != "" {
+		fmt.Fprintf(c, " Alt=%q", op.Alt)
+	}
+}

pkg/md/zstring.go

@@ -15,31 +15,33 @@ func _() {
 	_ = x[OpHeadingEnd-4]
 	_ = x[OpCodeBlockStart-5]
 	_ = x[OpCodeBlockEnd-6]
-	_ = x[OpParagraphStart-7]
-	_ = x[OpParagraphEnd-8]
-	_ = x[OpBlockquoteStart-9]
-	_ = x[OpBlockquoteEnd-10]
-	_ = x[OpListItemStart-11]
-	_ = x[OpListItemEnd-12]
-	_ = x[OpBulletListStart-13]
-	_ = x[OpBulletListEnd-14]
-	_ = x[OpOrderedListStart-15]
-	_ = x[OpOrderedListEnd-16]
-	_ = x[OpCodeSpanStart-17]
-	_ = x[OpCodeSpanEnd-18]
-	_ = x[OpEmphasisStart-19]
-	_ = x[OpEmphasisEnd-20]
-	_ = x[OpStrongEmphasisStart-21]
-	_ = x[OpStrongEmphasisEnd-22]
-	_ = x[OpLinkStart-23]
-	_ = x[OpLinkEnd-24]
-	_ = x[OpImage-25]
-	_ = x[OpHardLineBreak-26]
+	_ = x[OpHTMLBlockStart-7]
+	_ = x[OpHTMLBlockEnd-8]
+	_ = x[OpParagraphStart-9]
+	_ = x[OpParagraphEnd-10]
+	_ = x[OpBlockquoteStart-11]
+	_ = x[OpBlockquoteEnd-12]
+	_ = x[OpListItemStart-13]
+	_ = x[OpListItemEnd-14]
+	_ = x[OpBulletListStart-15]
+	_ = x[OpBulletListEnd-16]
+	_ = x[OpOrderedListStart-17]
+	_ = x[OpOrderedListEnd-18]
+	_ = x[OpCodeSpanStart-19]
+	_ = x[OpCodeSpanEnd-20]
+	_ = x[OpEmphasisStart-21]
+	_ = x[OpEmphasisEnd-22]
+	_ = x[OpStrongEmphasisStart-23]
+	_ = x[OpStrongEmphasisEnd-24]
+	_ = x[OpLinkStart-25]
+	_ = x[OpLinkEnd-26]
+	_ = x[OpImage-27]
+	_ = x[OpHardLineBreak-28]
 }
 
-const _OpType_name = "OpTextOpRawHTMLOpThematicBreakOpHeadingStartOpHeadingEndOpCodeBlockStartOpCodeBlockEndOpParagraphStartOpParagraphEndOpBlockquoteStartOpBlockquoteEndOpListItemStartOpListItemEndOpBulletListStartOpBulletListEndOpOrderedListStartOpOrderedListEndOpCodeSpanStartOpCodeSpanEndOpEmphasisStartOpEmphasisEndOpStrongEmphasisStartOpStrongEmphasisEndOpLinkStartOpLinkEndOpImageOpHardLineBreak"
+const _OpType_name = "OpTextOpRawHTMLOpThematicBreakOpHeadingStartOpHeadingEndOpCodeBlockStartOpCodeBlockEndOpHTMLBlockStartOpHTMLBlockEndOpParagraphStartOpParagraphEndOpBlockquoteStartOpBlockquoteEndOpListItemStartOpListItemEndOpBulletListStartOpBulletListEndOpOrderedListStartOpOrderedListEndOpCodeSpanStartOpCodeSpanEndOpEmphasisStartOpEmphasisEndOpStrongEmphasisStartOpStrongEmphasisEndOpLinkStartOpLinkEndOpImageOpHardLineBreak"
 
-var _OpType_index = [...]uint16{0, 6, 15, 30, 44, 56, 72, 86, 102, 116, 133, 148, 163, 176, 193, 208, 226, 242, 257, 270, 285, 298, 319, 338, 349, 358, 365, 380}
+var _OpType_index = [...]uint16{0, 6, 15, 30, 44, 56, 72, 86, 102, 116, 132, 146, 163, 178, 193, 206, 223, 238, 256, 272, 287, 300, 315, 328, 349, 368, 379, 388, 395, 410}
 
 func (i OpType) String() string {
 	if i >= OpType(len(_OpType_index)-1) {