🐛 Print user messages to stderr (#27)

Previously, any messages only intended for the user (status messages,
warnings, errors) were sent over stdout. The actual emoji items are also
sent to the pickers over stdout so they would sometimes pick up the
messages and show them as an option to pick. If history is enabled, we
then also save the falsely included items there to forever display as an
option.

This commit changes internal messages to all be sent over stderr
instead, so they should not be picked up by any external programs we
hand off to.

CHANGELOG.md

@@ -38,6 +38,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Always download from newest emoji list url
 - Pass selection to custom typing tools through stdin
+- Pass info messages to stderr to avoid passing to picker tools
 
 <!-- ### Security -->
 

bemoji

@@ -59,6 +59,11 @@ version() {
     exit
 }
 
+msg() {
+# Outputs a message to stderr, to be used for info, warning and error messages.
+    printf "%s\n" "$1" >&2
+}
+
 parse_cli() {
 	while getopts cD:ef:hnpP:tv-: arg "$@"; do
 		case "$arg" in
@@ -130,7 +135,7 @@ prepare_db() {
     if [ -n "$BEMOJI_DOWNLOAD_LIST" ]; then
         # Populate default lists
         if echo "$BEMOJI_DOWNLOAD_LIST" | grep -q -e 'none'; then
-            printf "Not downloading a default emoji list.\n"
+            msg "Not downloading a default emoji list."
             return
         elif echo "$BEMOJI_DOWNLOAD_LIST" | grep -q -e 'all'; then
             dl_default_emoji
@@ -158,19 +163,19 @@ dl_default_emoji() {
     local emojis
     emojis=$(curl -sSL "https://unicode.org/Public/emoji/latest/emoji-test.txt")
     printf "%s" "$emojis" | sed -ne 's/^.*; fully-qualified.*# \(\S*\) \S* \(.*$\)/\1 \2/gp' >"$bm_db_location/emojis.txt"
-    printf "Downloaded default emoji set.\n"
+    msg "Downloaded default emoji set."
 }
 dl_math_symbols() {
     curl -sSL "https://unicode.org/Public/math/latest/MathClassEx-15.txt" |
         grep -ve '^#' | cut -d';' -f3,7 | sed -e 's/;/ /' >"$bm_db_location/math.txt"
-    printf "Downloaded math symbols set.\n"
+    msg "Downloaded math symbols set."
 }
 dl_nerd_symbols() {
     local nerd all
     nerd=$(curl -sSL "https://raw.githubusercontent.com/ryanoasis/nerd-fonts/master/css/nerd-fonts-generated.css")
     all+=$(printf "%s" "$nerd" | sed -ne '/\.nf-/p' -e '/\s*[^_]content:/p' | sed -e 'N;s/^\.nf-\(.*\):before.* content: \"\\\(.*\)\";/\\U\2 \1/')
     echo -e "$all" > "$bm_db_location/nerdfont.txt"
-    printf "Downloaded nerdfont symbols set.\n"
+    msg "Downloaded nerdfont symbols set."
 }
 
 gather_emojis() {
@@ -231,7 +236,7 @@ _clipper() {
     elif [ -n "$DISPLAY" ] && command -v xsel >/dev/null 2>&1; then
         xsel -b
     else
-        printf "No suitable clipboard tool found."
+        msg "No suitable clipboard tool found."
         exit 1
     fi
 }
@@ -250,7 +255,7 @@ _typer() {
     elif [ -n "$DISPLAY" ] && command -v xdotool >/dev/null 2>&1; then
         xdotool type --delay 30 "$totype"
     else
-        printf "No suitable typing tool found."
+        msg "No suitable typing tool found."
         exit 1
     fi
 }
@@ -270,7 +275,7 @@ _picker() {
 		fi
 	done
 
-	printf "No suitable picker tool found." 1>&2
+	msg "No suitable picker tool found."
 	exit 1
 }
 

test/bemoji_errors.bats

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+setup_file() {
+    # make bemoji executable from anywhere relative to current testfile
+    TEST_DIR="$( cd "$( dirname "$BATS_TEST_FILENAME" )" >/dev/null 2>&1 && pwd )"
+    PATH="$TEST_DIR/..:$PATH"
+}
+
+setup() {
+    load 'test_helper/bats-support/load'
+    load 'test_helper/bats-assert/load'
+
+    # set up small default set of test emoji for each test
+    export BEMOJI_DB_LOCATION="$BATS_TEST_TMPDIR/database"
+    export BEMOJI_HISTORY_LOCATION="$BATS_TEST_TMPDIR/history"
+    mkdir -p "$BEMOJI_DB_LOCATION" "$BEMOJI_HISTORY_LOCATION"
+    cat "$BATS_TEST_DIRNAME/resources/test_emoji.txt" > "$BEMOJI_DB_LOCATION/emoji.txt"
+
+    # these tests require stdout to be separated from stderr
+    # such run flags were only introduced in recent bats version
+    bats_require_minimum_version 1.5.0
+}
+
+@test "Prints clipper error to stderr" {
+    BEMOJI_PICKER_CMD="echo hi" run --separate-stderr bemoji 3>&-
+    assert_output ""
+    output="$stderr"
+    assert_output "No suitable clipboard tool found."
+}
+
+@test "Prints picker error to stderr" {
+    run --separate-stderr bemoji 3>&-
+    assert_output ""
+    output="$stderr"
+    assert_output "No suitable picker tool found."
+}
+
+@test "Prints typer error to stderr" {
+    BEMOJI_PICKER_CMD="echo hi" run --separate-stderr bemoji -t 3>&-
+    assert_output ""
+    output="$stderr"
+    assert_output "No suitable typing tool found."
+}