Stop traffic search matching inside words

CHANGELOG.md

@@ -8,6 +8,14 @@ SPDX-License-Identifier: CC0-1.0
 
 All notable changes to `odh-cli` are documented here.
 
+## Unreleased
+
+- `traffic search` no longer matches alphabetic terms inside other words.
+  Searching `auer` used to hit every `Stützmauern` notice; terms now match at a
+  word boundary (prefix still allowed, so cycle aliases like `radweg` keep
+  finding `Radrouten`). Road-number spelling (`SS12` / `SS 12`) is unchanged.
+  Refs #12.
+
 ## v0.6.1 - 2026-08-04
 
 - Removed a helper left behind by the v0.6.0 zone-filter refactor. It was dead

internal/commands/traffic.go

@@ -757,7 +757,10 @@ func trafficSearchMatches(event trafficEvent, search string) bool {
 			if term == "" {
 				continue
 			}
-			if strings.Contains(haystack, term) || slices.Contains(identifiers, term) {
+			// Alphabetic terms match at a word boundary only (prefix of a word is
+			// fine: cycle aliases like "radweg" must still find "Radrouten"). An
+			// infix match would turn "auer" into every "Stützmauern".
+			if trafficTextHasTerm(haystack, term) || slices.Contains(identifiers, term) {
 				matched = true
 				break
 			}
@@ -773,6 +776,17 @@ func trafficSearchMatches(event trafficEvent, search string) bool {
 	return true
 }
 
+// trafficTextHasTerm reports whether term sits at the start of any word in
+// haystack. Prefixes are allowed; infix matches inside a longer word are not.
+func trafficTextHasTerm(haystack, term string) bool {
+	for _, word := range strings.Fields(haystack) {
+		if strings.HasPrefix(word, term) {
+			return true
+		}
+	}
+	return false
+}
+
 func trafficSearchTermGroups(search string) [][]string {
 	terms := joinRoadTokens(strings.Fields(normalizeTrafficSearchText(search)))
 	groups := make([][]string, 0, len(terms))

internal/commands/traffic_test.go

@@ -60,3 +60,29 @@ func TestTrafficSearchCycleAliasesAgree(t *testing.T) {
 		}
 	}
 }
+
+// Place-name searches must not match inside unrelated words. "auer" is a real
+// Unterland municipality; matching "Stützmauern" made the content search lie.
+func TestTrafficSearchRequiresWordBoundary(t *testing.T) {
+	wall := trafficEvent{Place: "Bei Moos im Bereich Stuller Wasserfall: Stützmauern erneuern"}
+	if trafficSearchMatches(wall, "auer") {
+		t.Error("auer must not match inside Stützmauern")
+	}
+	town := trafficEvent{Place: "Auer: Baustelle auf der Hauptstrasse"}
+	if !trafficSearchMatches(town, "auer") {
+		t.Error("auer must still match the municipality name as a word")
+	}
+	// Cycle aliases stay prefix matches at a word boundary: "radweg" finds
+	// "Radrouten", and road numbers keep their own spelling path.
+	routes := trafficEvent{Place: "Die Radrouten und die ciclabile bei Auer sind gesperrt"}
+	if !trafficSearchMatches(routes, "radweg") {
+		t.Error("radweg must still prefix-match Radrouten")
+	}
+	if !trafficSearchMatches(routes, "ciclabil") {
+		t.Error("ciclabil must still prefix-match ciclabile")
+	}
+	road := trafficEvent{Place: "Kreuzung mit der SS 12 Brennerstaatsstrasse"}
+	if !trafficSearchMatches(road, "ss12") {
+		t.Error("ss12 must still match spaced road numbers")
+	}
+}