test: port the enumerator-capacity observer to ww

test/xmod/enumcap_test.ww

@@ -0,0 +1,109 @@
+package enumcap_test;
+
+// #65 (F13 c3) driver directory-enumerator capacity gate. Port of the
+// retired native carrier test/wcc/989_enumcap_run.c; every assertion
+// preserved. The module tree is GENERATED at runtime (301 files on the
+// big row) -- it cannot be checked in as a fixture.
+//
+// Pre-c3 the wwstage enumeratedir silently capped at 256 files while
+// cstage grows unbounded: a >256-file module dir bundled a silently
+// divergent package unit under rc=0. Per row (big_300, small_5
+// control), both driver builds must succeed, each stage's
+// <stem>.sepwork/bigmod.unit.ww must hold EXACTLY nfiles
+// line-anchored `package bigmod;` clauses, and the two units must be
+// byte-identical (the decisive rule-10 leg -- a cap-drop on either
+// side shrinks its unit).
+//
+// Dropped C machinery, not assertions: the ww_ww-absent skip gate
+// (the Make target declares both drivers) and the per-file cleanup
+// accounting (testenv.clean asserts the removal).
+
+import os;
+import os.exec;
+import strconv;
+import strings;
+import testenv;
+import time;
+
+fn fail(label: str, why: str) void = {
+	let m: str = strings.concat("enumcap FAIL: ", label, " -- ", why,
+		"\n");
+	os.write(2, m.ptr, m.len: u64);
+	assert(false);
+};
+
+fn tmo() time.duration = {
+	return (240i64 * (time.second: i64)): time.duration;
+};
+
+// -1 encodes an abnormal (non-EXIT) termination, never a valid code.
+fn runcode(dir: str, name: str, argv: []str) i32 = {
+	let co: testenv.commandout;
+	testenv.runcommand(dir, dir, name, argv, tmo(), &co);
+	if (co.termination != exec.termination.EXIT) { return -1; };
+	return co.code;
+};
+
+// itos returns a view into a static buffer; dup materializes it so two
+// numbers can coexist in one concat.
+fn dec(n: i32) str = {
+	return strings.dup(strconv.itos(n: int, strconv.base.DEC));
+};
+
+fn pad3(n: i32) str = {
+	let d: str = dec(n);
+	if (n < 10) { return strings.concat("00", d); };
+	if (n < 100) { return strings.concat("0", d); };
+	return d;
+};
+
+// line-anchored `package bigmod;` clause count; the '\n' prepend
+// counts a file-leading clause too.
+fn countpkg(path: str) i32 = {
+	let body: str = strings.concat("\n", testenv.readfile(path));
+	return testenv.occurrences(body, "\npackage bigmod;");
+};
+
+fn row(label: str, nfiles: i32) void = {
+	let td: str = testenv.fresh();
+	assert(os.mkdir(strings.concat(td, "/bigmod"), 493) == 0);
+	let i: i32 = 0;
+	for (i < nfiles) {
+		let nn: str = pad3(i);
+		testenv.writefile(strings.concat(td, "/bigmod/f", nn, ".ww"),
+			strings.concat("package bigmod;\nexport fn f", nn,
+				"() i32 = { return ", dec(i), "; };\n"));
+		i += 1;
+	};
+	let mainww: str = strings.concat(td, "/main.ww");
+	testenv.writefile(mainww,
+		"package main;\nimport bigmod;\nfn main() void = {};\n");
+
+	let drvs: []str = ["ww", "ww_ww"];
+	let stems: []str = ["X_c", "X_w"];
+	let units: []str = ["", ""];
+	let s: i32 = 0;
+	for (s < 2) {
+		let stem: str = strings.concat(td, "/", stems[s]);
+		let av: []str = [testenv.driver(drvs[s]), "build", "-o", stem,
+			mainww];
+		if (runcode(td, strings.concat("build_", stems[s]), av) != 0) {
+			fail(label, strings.concat(drvs[s], " build failed"));
+		};
+		units[s] = strings.concat(stem, ".sepwork/bigmod.unit.ww");
+		if (countpkg(units[s]) != nfiles) {
+			fail(label, strings.concat(drvs[s], " enrolled clause count ",
+				"!= nfiles (silent enumerator cap -- #65)"));
+		};
+		s += 1;
+	};
+	if (!testenv.same(testenv.readfile(units[0]),
+		testenv.readfile(units[1]))) {
+		fail(label, "cs/ww bigmod.unit.ww differ (#65)");
+	};
+	testenv.clean(td);
+};
+
+@test fn big_300() void = { row("big_300", 300); };
+
+@test fn small_5() void = { row("small_5", 5); };