test: initial tests for external commands

The main goal is to test the setting of NOTMUCH_CONFIG, but also
include a basic sanity test for execing scripts.

test/T405-external.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+test_description='hooks'
+. $(dirname "$0")/test-lib.sh || exit 1
+
+create_echo_script () {
+    local TOKEN="${RANDOM}"
+    mkdir -p ${BIN_DIR}
+    cat <<EOF >"${BIN_DIR}/${1}"
+#!/bin/sh
+echo "${TOKEN}" > ${3}
+EOF
+    chmod +x "${BIN_DIR}/${1}"
+    echo "${TOKEN}" > ${2}
+}
+
+create_printenv_script () {
+    mkdir -p ${BIN_DIR}
+    cat <<EOF >"${BIN_DIR}/${1}"
+#!/bin/sh
+printenv "${2}" > "${3}"
+EOF
+    chmod +x "${BIN_DIR}/${1}"
+}
+
+# add a message to generate mail dir and database
+add_message
+
+BIN_DIR=`pwd`/bin
+PATH=$BIN_DIR:$PATH
+
+test_begin_subtest "'notmuch foo' runs notmuch-foo"
+rm -rf ${BIN_DIR}
+create_echo_script "notmuch-foo" EXPECTED OUTPUT $HOOK_DIR
+notmuch foo
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
+create_printenv_script "notmuch-printenv" NOTMUCH_CONFIG OUTPUT
+
+test_begin_subtest "NOTMUCH_CONFIG is set"
+notmuch printenv
+cat <<EOF > EXPECTED
+${NOTMUCH_CONFIG}
+EOF
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
+test_begin_subtest "NOTMUCH_CONFIG is set by --config"
+test_subtest_known_broken
+cp "${NOTMUCH_CONFIG}" "${NOTMUCH_CONFIG}.alternate"
+cat <<EOF > EXPECTED
+${NOTMUCH_CONFIG}.alternate
+EOF
+notmuch --config "${NOTMUCH_CONFIG}.alternate" printenv
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
+test_done