fix for /usr/bin/wc on freebsd (#1338)

* fix for /usr/bin/wc on freebsd
* check for python3 in bats-test

tests/README.md

@@ -279,7 +279,12 @@ it with `run jq <(output)` you can only do it once, because the second time it
 will read the output of the `jq` command. But you can construct a list of all
 the values you want and check them all in a single step.
 
-See `lib/setup_file.sh` for other tricks we employ.
+Note that `<(output)` is substituted with the file name of a file descriptor,
+so `mycmd <(output)` can become `mycmd /dev/fd/23`, `mycmd /tmp//sh-np.hpc7Zs`
+or `mycmd /proc/self/fd/38` depending on the platform. To have it fed to
+standard input, use `< <(output)`.
+
+See the `lib/*.sh` and `bats/*.bats` files for other tricks we employ.
 
 ## file operations
 

tests/bats/70_plugins.bats

@@ -54,6 +54,8 @@ setup() {
 
 @test "$FILE expected 1 log line from http server" {
     run -0 wc -l <"${MOCK_OUT}"
+    # wc can pad with spaces on some platforms
+    run -0 tr -d ' ' < <(output)
     assert_output 1
 }
 

tests/run-tests

@@ -15,6 +15,10 @@ TEST_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
 
 
 check_requirements() {
+    if ! command -v python3 >/dev/null; then
+        die "missing required program 'python3'"
+    fi
+
     if ! command -v nc >/dev/null; then
         die "missing required program 'nc' (package 'netcat-openbsd')"
     fi