Fix interactive input for curl ... | bash style installation (#51)

Author: kateinoigakukun

install/swiftly-install.sh

@@ -25,7 +25,15 @@ has_command () {
 
 read_input_with_default () {
     echo -n "> "
-    read READ_INPUT_RETURN
+    # The installer script is usually run by "curl ... | bash", which means that
+    # stdin is not a tty but the script content itself. In that case, "read" builtin
+    # command receives EOF immediately. To avoid that, we use /dev/tty as stdin explicitly.
+    # SWIFTLY_READ_FROM_STDIN is used for testing interactive input
+    if [[ -t 0 ]] || [[ ${SWIFTLY_READ_FROM_STDIN+set} == "set" ]]; then
+        read READ_INPUT_RETURN
+    else
+        read READ_INPUT_RETURN < /dev/tty
+    fi
 
     if [ -z "$READ_INPUT_RETURN" ]; then
         READ_INPUT_RETURN="$1"

install/test-util.sh

@@ -2,6 +2,8 @@
 
 # Common utility functionality used in the various bash tests for swiftly-install.sh.
 
+export SWIFTLY_READ_FROM_STDIN=1
+
 has_command () {
     command -v "$1" > /dev/null
 }

install/tests/overwrite.sh

@@ -27,7 +27,7 @@ echo "$DUMMY_CONFIG_CONTENTS" > "$SWIFTLY_HOME_DIR/config.json"
 mkdir "$SWIFTLY_HOME_DIR/toolchains/5.7.3"
 
 # Attempt the same installation, but decline to overwrite.
-printf "1\nn\n" | ./swiftly-install.sh 
+printf "1\nn\n" | ./swiftly-install.sh
 
 if ! has_command "swiftly" ; then
     test_fail "Can't find swiftly on the PATH"
@@ -43,7 +43,7 @@ if [[ ! -d "$SWIFTLY_HOME_DIR/toolchains/5.7.3" ]]; then
 fi
 
 # Attempt the same installation, but overwrite this time.
-printf "1\ny\n" | ./swiftly-install.sh 
+printf "1\ny\n" | ./swiftly-install.sh
 
 if ! has_command "swiftly" ; then
     test_fail "Can't find swiftly on the PATH"