From 0d72c2bede9acc83ffba994f09388e9912ec3578 Mon Sep 17 00:00:00 2001
From: Yug Patel <5773665+Detoy@users.noreply.github.com>
Date: Wed, 7 Oct 2026 14:32:16 +0530
Subject: [PATCH 1/2] Reject a -sites list with no site keys instead of
 panicking

`crawl -sites ","` resolved to an empty key list but was accepted, so
the single-site path indexed siteKeys[0] and panicked. `watch -sites ","`
started and idled forever watching zero sites.

Treat a -sites value with no keys as if it was not given. Both commands
now print "one of -site, -sites, or --all-sites is required" and exit 1,
and an empty -sites next to a -site no longer discards that -site.

Fixes #13
---
 cmd/doc-scraper/exec_test.go | 11 +++++++++++
 cmd/doc-scraper/main.go      | 15 ++++++++-------
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/cmd/doc-scraper/exec_test.go b/cmd/doc-scraper/exec_test.go
index 75ebdfd..1858929 100644
--- a/cmd/doc-scraper/exec_test.go
+++ b/cmd/doc-scraper/exec_test.go
@@ -164,6 +164,17 @@ func TestResolveSiteKeys(t *testing.T) {
 
 	_, _, ok = resolveSiteKeys("", "", false)
 	assert.False(t, ok)
+
+	// A -sites list with no keys selects nothing, so it is not a selector.
+	for _, sites := range []string{",", " , ,", " "} {
+		_, _, ok = resolveSiteKeys("", sites, false)
+		assert.False(t, ok, "-sites %q", sites)
+	}
+
+	keys, warning, ok = resolveSiteKeys("a", ",", false)
+	assert.True(t, ok)
+	assert.Equal(t, []string{"a"}, keys)
+	assert.Empty(t, warning)
 }
 
 func TestLogHelpers(t *testing.T) {
diff --git a/cmd/doc-scraper/main.go b/cmd/doc-scraper/main.go
index 9e8e177..71bee58 100644
--- a/cmd/doc-scraper/main.go
+++ b/cmd/doc-scraper/main.go
@@ -167,6 +167,7 @@ func extraArgsError(fs *flag.FlagSet) error {
 // resolveSiteKeys picks the crawl target in precedence --all-sites > -sites >
 // -site. warning is non-empty when a lower-precedence selector was also set and
 // silently ignored, so a typo'd -site next to a valid -sites is not missed.
+// A -sites list with no keys in it (e.g. ",") counts as not given.
 func resolveSiteKeys(siteKey, sites string, allSites bool) (siteKeys []string, warning string, ok bool) {
 	if allSites {
 		if sites != "" || siteKey != "" {
@@ -174,16 +175,16 @@ func resolveSiteKeys(siteKey, sites string, allSites bool) (siteKeys []string, w
 		}
 		return nil, warning, true
 	}
-	if sites != "" {
+	for _, s := range strings.Split(sites, ",") {
+		s = strings.TrimSpace(s)
+		if s != "" {
+			siteKeys = append(siteKeys, s)
+		}
+	}
+	if len(siteKeys) > 0 {
 		if siteKey != "" {
 			warning = "both -site and -sites given; using -sites and ignoring -site"
 		}
-		for _, s := range strings.Split(sites, ",") {
-			s = strings.TrimSpace(s)
-			if s != "" {
-				siteKeys = append(siteKeys, s)
-			}
-		}
 		return siteKeys, warning, true
 	}
 	if siteKey != "" {

From 71944119107b85ab5581f56546d5e80b68c700a1 Mon Sep 17 00:00:00 2001
From: Yug Patel <5773665+Detoy@users.noreply.github.com>
Date: Wed, 7 Oct 2026 19:28:05 +0530
Subject: [PATCH 2/2] Warn when an empty -sites list falls back to -site

---
 cmd/doc-scraper/exec_test.go | 2 +-
 cmd/doc-scraper/main.go      | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/cmd/doc-scraper/exec_test.go b/cmd/doc-scraper/exec_test.go
index 1858929..764336c 100644
--- a/cmd/doc-scraper/exec_test.go
+++ b/cmd/doc-scraper/exec_test.go
@@ -174,7 +174,7 @@ func TestResolveSiteKeys(t *testing.T) {
 	keys, warning, ok = resolveSiteKeys("a", ",", false)
 	assert.True(t, ok)
 	assert.Equal(t, []string{"a"}, keys)
-	assert.Empty(t, warning)
+	assert.Equal(t, "-sites has no site keys; using -site", warning)
 }
 
 func TestLogHelpers(t *testing.T) {
diff --git a/cmd/doc-scraper/main.go b/cmd/doc-scraper/main.go
index 71bee58..4f3beb6 100644
--- a/cmd/doc-scraper/main.go
+++ b/cmd/doc-scraper/main.go
@@ -167,7 +167,8 @@ func extraArgsError(fs *flag.FlagSet) error {
 // resolveSiteKeys picks the crawl target in precedence --all-sites > -sites >
 // -site. warning is non-empty when a lower-precedence selector was also set and
 // silently ignored, so a typo'd -site next to a valid -sites is not missed.
-// A -sites list with no keys in it (e.g. ",") counts as not given.
+// A -sites list with no keys in it (e.g. ",") counts as not given; if -site
+// is also set it is used, with a warning.
 func resolveSiteKeys(siteKey, sites string, allSites bool) (siteKeys []string, warning string, ok bool) {
 	if allSites {
 		if sites != "" || siteKey != "" {
@@ -188,7 +189,10 @@ func resolveSiteKeys(siteKey, sites string, allSites bool) (siteKeys []string, w
 		return siteKeys, warning, true
 	}
 	if siteKey != "" {
-		return []string{siteKey}, "", true
+		if sites != "" {
+			warning = "-sites has no site keys; using -site"
+		}
+		return []string{siteKey}, warning, true
 	}
 	return nil, "", false
 }