fix(update): fix issue when SHA cannot be found

* add support for force updating prompt

* ignore update-prompt check when the SHA cannot be retrieved from github

* resolve an issue where a variable in add-var may be placed on the current line in the event that the file does not end in a newline (POSIX)

* delete-prefix on nvm-use

* remove backups when updating prompt

src/scripts/add-var.sh

@@ -30,7 +30,7 @@ add-var() {
     local varpath="$AM_PROMPT/user/variables.sh"
 
     echo Adding varable: $v
-    echo $v >> "$varpath"
+    echo "\n$v" >> "$varpath"
     source "$varpath"
 }
 

src/scripts/git-extras.sh

@@ -38,7 +38,19 @@ git-sha() {
     local SHA_URI=https://api.github.com/repos/$ORG_NAME/$REPO_NAME/commits/$BRANCH_NAME
     local SHA=$(curl $CURL_OPT $SHA_URI | grep sha | head -n 1 | sed 's#.*\:.*"\(.*\).*",#\1#')
 
-    echo $SHA
+    if [ ! -z "${AM_PROMPT_DEBUG:-}" ]; then
+        echo "curl $CURL_OPT $SHA_URI"
+    fi
+
+    if [ ! -z "${SHA:-}" ]; then
+        echo $SHA
+        return 0
+    fi
+
+    echo "ERROR RETRIEVING GIT SHA FOR $SHA_URI"
+    echo "$(curl $CURL_OPT $SHA_URI)"
+
+    return 1
 }
 
 git-token() {

src/scripts/set-nvm.sh

@@ -21,6 +21,6 @@ __prompt-set-nvm()
         source "$nvm_path/nvm.sh"
     fi
 
-    nvm use --lts
+    nvm use --lts --delete-prefix
     eval "$(npm completion)"
 }

src/scripts/update-prompt.sh

@@ -8,13 +8,24 @@ update-prompt() {
     local SHA=$(git-sha)
     local SHA_PATH=$HOME/.am/prompt/.sha
 
-    if [ -f $SHA_PATH ]; then
+    if [ "${1:-}" = "--force" ]; then
+        rm -rf $SHA_PATH 1>/dev/null 2>&1
+    fi
+
+    remove-backup
+
+    if [ -f "${SHA_PATH:-}" ]; then
         CURRENT_SHA=$(cat $SHA_PATH)
 
-        if [ $SHA = $CURRENT_SHA ]; then
-            echo "prompt: latest version already installed: $SHA"
+        if [ -z "${SHA:-}" ]; then
+            echo "prompt: SHA cannot be retrieved, which could be related to rate limiting."
             return 1
         fi
+
+        if [ "${SHA:-}" = "${CURRENT_SHA:-}" ]; then
+            echo "prompt: latest version already installed: $SHA"
+            return 0
+        fi
     fi
 
     local CHANGELOG_URI="https://github.com/automotivemastermind/prompt/blob/master/CHANGELOG.md"

uname/install-Darwin.sh

@@ -56,7 +56,7 @@ __prompt-install-darwin() {
         source "$nvm_path/nvm.sh"
 
         nvm install --lts 1>/dev/null 2>&1
-        nvm use --lts 1>/dev/null 2>&1
+        nvm use --lts --delete-prefix 1>/dev/null 2>&1
     fi
 
     __prompt-success 'setting git credential helper to use the macOS keychain'

uname/install-debian.sh

@@ -24,4 +24,4 @@ sudo apt-get autoremove -y 1>/dev/null
 
 curl -o- https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash
 nvm install --lts 1>/dev/null
-nvm use --lts 1>/dev/null
+nvm use --lts --delete-prefix 1>/dev/null

uname/install-fedora.sh

@@ -12,6 +12,6 @@ done
 
 curl -o- https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash
 nvm install --lts 1>/dev/null
-nvm use --lts 1>/dev/null
+nvm use --lts --delete-prefix 1>/dev/null
 
 wget --no-check-certificate -q  https://raw.github.com/petervanderdoes/gitflow-avh/develop/contrib/gitflow-installer.sh && sudo bash gitflow-installer.sh install stable; rm gitflow-installer.sh

uname/install-ubuntu.sh

@@ -24,4 +24,4 @@ sudo apt-get autoremove -y 1>/dev/null
 
 curl -o- https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash
 nvm install --lts 1>/dev/null
-nvm use --lts 1>/dev/null
+nvm use --lts --delete-prefix 1>/dev/null