Add more tests for serial() -- set to true at various ESI levels.

src/tests/serial.vtc

-varnishtest "basic test for serial processing"
-
-# XXX @geoff please add more
+varnishtest "serial processing"
 
 server s1 {
 	rxreq
@@ -157,3 +155,218 @@ client c1 {
 	}
 	} -run
 } -run
+
+## Set serial(true) at different ESI levels.
+
+server s1 -wait
+server s2 -wait
+
+server s1 {
+	rxreq
+	txresp -body {<Before esi1>
+<esi:include src="/esi1.html"/>
+Between esi1 and esi2
+<esi:include src="/esi2.html"/>
+After esi2
+}
+} -start
+
+server s2 {
+	rxreq
+	expect req.url == "/esi1.html"
+	txresp -body {<Before esi1-1>
+<esi:include src="/esi1-1.html"/>
+Between esi1-1 and esi1-2
+<esi:include src="/esi1-2.html"/>
+After esi1-2
+}
+} -start
+
+server s3 {
+	rxreq
+	expect req.url == "/esi2.html"
+	txresp -body {<Before esi2-1>
+<esi:include src="/esi2-1.html"/>
+Between esi2-1 and esi2-2
+<esi:include src="/esi2-2.html"/>
+After esi2-2
+}
+} -start
+
+server s4 {
+	loop 4 {
+		rxreq
+		expect req.url == "/esi1-1.html"
+		txresp -hdr "Cache-Control: max-age=0" -body {esi1-1
+}
+	}
+} -start
+
+server s5 {
+	loop 4 {
+		rxreq
+		expect req.url == "/esi1-2.html"
+		txresp -hdr "Cache-Control: max-age=0" -body {esi1-2
+}
+	}
+} -start
+
+server s6 {
+	loop 4 {
+		rxreq
+		expect req.url == "/esi2-1.html"
+		txresp -hdr "Cache-Control: max-age=0" -body {esi2-1
+}
+	}
+} -start
+
+server s7 {
+	loop 4 {
+		rxreq
+		expect req.url == "/esi2-2.html"
+		txresp -hdr "Cache-Control: max-age=0" -body {esi2-2
+}
+	}
+} -start
+
+varnish v1 -vcl+backend {
+	import ${vmod_pesi};
+	import std;
+
+	sub vcl_backend_fetch {
+		if (bereq.url == "/") {
+			set bereq.backend = s1;
+		}
+		elsif (bereq.url == "/esi1.html") {
+			set bereq.backend = s2;
+		}
+		elsif (bereq.url == "/esi2.html") {
+			set bereq.backend = s3;
+		}
+		elsif (bereq.url == "/esi1-1.html") {
+			set bereq.backend = s4;
+		}
+		elsif (bereq.url == "/esi1-2.html") {
+			set bereq.backend = s5;
+		}
+		elsif (bereq.url == "/esi2-1.html") {
+			set bereq.backend = s6;
+		}
+		elsif (bereq.url == "/esi2-2.html") {
+			set bereq.backend = s7;
+		}
+	}
+
+	sub vcl_backend_response {
+		set beresp.do_esi = true;
+	}
+
+	sub vcl_deliver {
+		pesi.activate();
+		if (std.integer(req.http.Serial-Level, -1) >= req.esi_level) {
+			pesi.serial(true);
+		}
+	}
+}
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.bodylen == 191
+	expect resp.body == {<Before esi1>
+<Before esi1-1>
+esi1-1
+
+Between esi1-1 and esi1-2
+esi1-2
+
+After esi1-2
+
+Between esi1 and esi2
+<Before esi2-1>
+esi2-1
+
+Between esi2-1 and esi2-2
+esi2-2
+
+After esi2-2
+
+After esi2
+}
+
+	txreq -hdr "Serial-Level: 0"
+	rxresp
+	expect resp.status == 200
+	expect resp.bodylen == 191
+	expect resp.body == {<Before esi1>
+<Before esi1-1>
+esi1-1
+
+Between esi1-1 and esi1-2
+esi1-2
+
+After esi1-2
+
+Between esi1 and esi2
+<Before esi2-1>
+esi2-1
+
+Between esi2-1 and esi2-2
+esi2-2
+
+After esi2-2
+
+After esi2
+}
+
+	txreq -hdr "Serial-Level: 1"
+	rxresp
+	expect resp.status == 200
+	expect resp.bodylen == 191
+	expect resp.body == {<Before esi1>
+<Before esi1-1>
+esi1-1
+
+Between esi1-1 and esi1-2
+esi1-2
+
+After esi1-2
+
+Between esi1 and esi2
+<Before esi2-1>
+esi2-1
+
+Between esi2-1 and esi2-2
+esi2-2
+
+After esi2-2
+
+After esi2
+}
+
+	txreq -hdr "Serial-Level: 2"
+	rxresp
+	expect resp.status == 200
+	expect resp.bodylen == 191
+	expect resp.body == {<Before esi1>
+<Before esi1-1>
+esi1-1
+
+Between esi1-1 and esi1-2
+esi1-2
+
+After esi1-2
+
+Between esi1 and esi2
+<Before esi2-1>
+esi2-1
+
+Between esi2-1 and esi2-2
+esi2-2
+
+After esi2-2
+
+After esi2
+}
+} -run