4 files changed, 39 insertions, 1 deletions
diff --git a/tests/drivers/completion_test.js b/tests/drivers/completion_test.js
index f1ee5e6..4b767a1 100644
--- a/tests/drivers/completion_test.js
+++ b/tests/drivers/completion_test.js
@@ -104,4 +104,15 @@ assert.match(get(r.items, 'map').documentation.value, /transform.*each element/)
 assert.ok(!r.items.some(c => ['push', 'pop', 'resize'].includes(c.label)), 'library algorithms do not make a fixed array growable');
 r = complete('include rt; fn main() { int[?] items = {}; items.| }');
 assert.ok(!r.items.some(c => ['map', 'filter'].includes(c.label)), 'library methods require an explicit import');
-console.log('ok   completion: signatures, docs, fuzzy ranking, scope, array members, shadowing and consumed lifetimes');
+r = complete('include std; fn main() { std.| }');
+for (const name of ['File', 'Io', 'Text', 'Host', 'argv', 'bnew']) get(r.items, name);
+assert.ok(!r.items.some(c => c.label.includes('.')), 'module completion lists one level: ' + r.items.filter(c => c.label.includes('.')).map(c => c.label));
+r = complete('include std; fn main() { std.File.| }');
+for (const name of ['read', 'write']) get(r.items, name);
+assert.ok(!r.items.some(c => ['Io', 'File', 'main', 'int'].includes(c.label)), 'group completion lists only its members');
+r = complete('include std; fn main() { std.Io.| }');
+for (const name of ['print', 'println', 'put_n', 'put_f', 'getline']) get(r.items, name);
+assert.ok(!r.items.some(c => ['write', 'itoa', 'main', 'int'].includes(c.label)), 'std.Io. lists only Io members');
+r = complete('include std; fn main() { std.Io.pr| }');
+assert.deepStrictEqual(r.items.map(c => c.label).sort(), ['print', 'println']);
+console.log('ok   completion: signatures, docs, fuzzy ranking, scope, array members, shadowing, consumed lifetimes and one level of a module path');
diff --git a/tests/programs/stdio.expected b/tests/programs/stdio.expected
new file mode 100644
index 0000000..4a7fd8a
--- /dev/null
+++ b/tests/programs/stdio.expected
@@ -0,0 +1,8 @@
+hi -42 2.500000
+line
+bytes 0xff s
+8 caught 7
+3:abc
+3:lon
+7 103
+-1 1
diff --git a/tests/programs/stdio.zc b/tests/programs/stdio.zc
new file mode 100644
index 0000000..5a79262
--- /dev/null
+++ b/tests/programs/stdio.zc
@@ -0,0 +1,18 @@
+include rt, std;
+
+// std.Io: the writers, a capture of them, and the line reader over program input.
+fn main() {
+	std.Io.print("hi "); std.Io.put_n(-42); std.Io.put_c(32); std.Io.put_f(2.5); std.Io.nl();
+	std.Io.println("line"); std.Io.put_bs(b"bytes"); std.Io.put_c(32); std.Io.put_hex(255);
+	std.Io.put_c(32); std.Io.put_s("s"); std.Io.nl();
+	let cap = std.capture.start();
+	std.Io.print("caught "); std.Io.put_n(7);
+	std.capture.end(cap);
+	std.Io.put_n(std.Text.len(cap)); std.Io.put_c(32); std.Io.println(cap);
+	char[32] buf; int n = std.Io.getline(buf, 32);
+	std.Io.put_n(n); std.Io.print(":"); std.Io.println(buf);
+	n = std.Io.getline(buf, 4); std.Io.put_n(n); std.Io.print(":"); std.Io.println(buf);
+	n = std.Io.read(buf, 32); std.Io.put_n(n); std.Io.put_c(32); std.Io.put_n(buf[0]); std.Io.nl();
+	n = std.Io.getline(buf, 32); std.Io.put_n(n); std.Io.put_c(32); std.Io.put_n(std.Io.eof()); std.Io.nl();
+	return 0;
+}
diff --git a/tests/test.sh b/tests/test.sh
index 8bf7a9b..7745a66 100755
--- a/tests/test.sh
+++ b/tests/test.sh
@@ -155,6 +155,7 @@ run(){	# $1 = vm command, $2 = label
 	chk "$($vm < tests/programs/use_std.zc)" "42 -7 1" "$l include and the string helpers"
 	chk "$($vm < tests/programs/stdbuf.zc)" "4 1 266 8" "$l stdlib arena and packed byte buffer"
 	chk "$($vm < tests/programs/stdmore.zc)" "$(printf '5 1 0 0 7 copy me 12 -1 0 1 0 1\n9 mixed 123 9 MIXED 123\n11 [padded line]\n42 3 9 10 12 81 9 10 -1 0\n6 1 2 -1 1 0')" "$l stdlib text, byte-string and num helpers"
+	chk "$( (cat tests/programs/stdio.zc; printf '`abc\nlonger\nxyz') | $vm)" "$(cat tests/programs/stdio.expected)" "$l std.Io writers, capture, getline and read"
 	chk "$(ZC_FILE=tests/data/hi.txt $vm < examples/cli.zc)" "6 h" "$l reading a file named by the environment"
 	chk "$(ZC_ARG_TEST=ok $vm < tests/programs/args.zc)" "1 <eval>  <eval> 1 1" "$l argv and envp from the host, argv[0] is <eval> on stdin"
 	chk "$(ZC_ARG_TEST=ok $vm < tests/programs/capture.zc)" "0