Files
swehockey/dom.go
T
Mats Tornberg 6b701819ca Deterministic swehockey.se schedule crawler
One HTTP GET per season, no browser: the page is server-rendered, so every row
arrives in one response and the extraction becomes a pure function of the HTML.

- layouts[] declares one profile per version of the site's table (modern and
  legacy), each identified by its header row, so a new version of the page is a
  new profile plus a fixture instead of a guess.
- The table is located by header signature, not by a CSS path.
- Every cell is shape-checked, and facts the site renders twice (desktop and
  mobile date, time in the tooltip) must agree.
- Cross-field invariants: periods sum to the score, ids are unique, played games
  always have an event link and unplayed ones never do.
- Output is sorted by date, time and id, so it does not inherit the site's row
  order, and it carries no fetch timestamp: same HTML, same bytes.
- Drift is a typed error and exit code 3, with the header it actually found.
- Tests run on committed HTML fixtures and golden JSON; TestLive is opt-in.

Verified over the full SHL archive: 27/27 seasons, 2119 games, 1779 played.
2026-09-27 08:47:25 +00:00

130 lines
2.8 KiB
Go

package main
import (
"crypto/sha256"
"encoding/hex"
"strings"
"unicode"
"golang.org/x/net/html"
)
// The site writes the team separator as NBSP-hyphen-NBSP wrapped in newlines,
// so every string that leaves the parser goes through normalize and downstream
// comparisons and diffs stay stable.
func normalize(s string) string {
return strings.Join(strings.FieldsFunc(s, isSpaceRune), " ")
}
func isSpaceRune(r rune) bool {
if unicode.IsSpace(r) {
return true
}
// No-break and zero-width variants the site emits around team names.
switch r {
case '\u00a0', '\u2007', '\u202f', '\u200b', '\ufeff':
return true
}
return false
}
// textOf returns the normalized text of a node subtree.
func textOf(n *html.Node) string {
if n == nil {
return ""
}
var b strings.Builder
var walk func(*html.Node)
walk = func(n *html.Node) {
if n.Type == html.TextNode {
b.WriteString(n.Data)
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
walk(c)
}
}
walk(n)
return normalize(b.String())
}
// textExcluding returns the normalized text of a node subtree with the first
// descendant matching skipTag (and its subtree) left out. The schedule uses
// this to read the mobile cell's start time without its <bold> date.
func textExcluding(n *html.Node, skipTag string) string {
if n == nil {
return ""
}
var b strings.Builder
var walk func(*html.Node) bool
walk = func(n *html.Node) bool {
if n.Type == html.ElementNode && n.Data == skipTag {
return false
}
if n.Type == html.TextNode {
b.WriteString(n.Data)
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
walk(c)
}
return true
}
walk(n)
return normalize(b.String())
}
// childElements returns the direct children of n with the given tag name.
func childElements(n *html.Node, tag string) []*html.Node {
if n == nil {
return nil
}
var out []*html.Node
for c := n.FirstChild; c != nil; c = c.NextSibling {
if c.Type == html.ElementNode && c.Data == tag {
out = append(out, c)
}
}
return out
}
// descendants returns every element with the given tag name, in document order.
func descendants(n *html.Node, tag string) []*html.Node {
var out []*html.Node
var walk func(*html.Node)
walk = func(n *html.Node) {
if n.Type == html.ElementNode && n.Data == tag {
out = append(out, n)
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
walk(c)
}
}
walk(n)
return out
}
func attr(n *html.Node, key string) string {
if n == nil {
return ""
}
for _, a := range n.Attr {
if a.Key == key {
return a.Val
}
}
return ""
}
func hasClass(n *html.Node, class string) bool {
for _, f := range strings.Fields(attr(n, "class")) {
if f == class {
return true
}
}
return false
}
func sha256Hex(b []byte) string {
sum := sha256.Sum256(b)
return hex.EncodeToString(sum[:])
}