tests: add script to verify static libraries (#237)

This is an subtle way for things to break, it's easy to accidentally
break it, and the check for it is not _that_ complicated, so we can
automate it.

Move both test scripts into the tests directory and invoke them from
there.

Author: kevinburke

Makefile

@@ -22,9 +22,12 @@ endif
 
 all: target/client target/server
 
-test: all
+test: all test-rust
+	./tests/verify-static-libraries.sh
+	./tests/client-server.sh
+
+test-rust:
 	cargo test
-	./test.sh
 
 target:
 	mkdir -p $@

test.sh renamed to tests/client-server.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+main() {
+    local -r uname=$(uname)
+    local want;
+    # If you need to change the values here, be sure to update the values in the
+    # README. Alternatively, it is possible that adding new libraries to link
+    # against was a mistake that should be reverted or worked around.
+    if [[ "${uname}" == 'Darwin' ]]; then
+        want='-framework Security -liconv -lSystem -lresolv -lc -lm -liconv'
+    elif [[ "${uname}" == 'Linux' ]]; then
+        want='-lgcc_s -lutil -lrt -lpthread -lm -ldl -lc'
+    else
+        # TODO
+        want=''
+    fi
+    # unfortunately --print native-static-libs does not yield the
+    # information in a machine consumable format, so we need to pull it
+    # out of stderr.
+    # https://users.rust-lang.org/t/print-native-static-libs/14102/14
+    if ! RUSTFLAGS="--print native-static-libs" cargo build 2>&1 >/dev/null | grep -q -F -x "note: native-static-libs: ${want}"; then
+        echo "got unexpected list of static libraries, fix or update README: ${want}"
+        exit 1
+    fi
+}
+
+main "$@"