[Refactor] prefer case over if/else chains

nvm.sh

@@ -136,15 +136,17 @@ nvm_download() {
     eval "curl -q --fail ${CURL_COMPRESSED_FLAG:-} ${CURL_HEADER_FLAG:-} ${NVM_DOWNLOAD_ARGS}"
   elif nvm_has "wget"; then
     # Emulate curl with wget
-    ARGS=$(nvm_echo "$@" | command sed -e 's/--progress-bar /--progress=bar /' \
+    ARGS=$(nvm_echo "$@" | command sed "
-                            -e 's/--compressed //' \
+      s/--progress-bar /--progress=bar /
-                            -e 's/--fail //' \
+      s/--compressed //
-                            -e 's/-L //' \
+      s/--fail //
-                            -e 's/-I /--server-response /' \
+      s/-L //
-                            -e 's/-s /-q /' \
+      s/-I /--server-response /
-                            -e 's/-sS /-nv /' \
+      s/-s /-q /
-                            -e 's/-o /-O /' \
+      s/-sS /-nv /
-                            -e 's/-C - /-c /')
+      s/-o /-O /
+      s/-C - /-c /
+    ")
 
     if [ -n "${NVM_AUTH_HEADER:-}" ]; then
       ARGS="${ARGS} --header \"${NVM_AUTH_HEADER}\""
@@ -1413,11 +1415,11 @@ nvm_add_iojs_prefix() {
 nvm_strip_iojs_prefix() {
   local NVM_IOJS_PREFIX
   NVM_IOJS_PREFIX="$(nvm_iojs_prefix)"
-  if [ "${1-}" = "${NVM_IOJS_PREFIX}" ]; then
+
-    nvm_echo
+  case "${1-}" in
-  else
+    "${NVM_IOJS_PREFIX}") nvm_echo ;;
-    nvm_echo "${1#"${NVM_IOJS_PREFIX}"-}"
+    *) nvm_echo "${1#"${NVM_IOJS_PREFIX}"-}" ;;
-  fi
+  esac
 }
 
 nvm_ls() {
@@ -1549,12 +1551,15 @@ nvm_ls() {
   fi
 
   if [ "${NVM_ADD_SYSTEM-}" = true ]; then
-    if [ -z "${PATTERN}" ] || [ "${PATTERN}" = 'v' ]; then
+    case "${PATTERN}" in
+      '' | v)
         VERSIONS="${VERSIONS}
 system"
-    elif [ "${PATTERN}" = 'system' ]; then
+      ;;
+      system)
         VERSIONS="system"
-    fi
+      ;;
+    esac
   fi
 
   if [ -z "${VERSIONS}" ]; then
@@ -1688,7 +1693,7 @@ EOF
     LTS="${LTS#lts/}"
   fi
 
-  VERSIONS="$({ command awk -v lts="${LTS-}" '{
+  VERSIONS="$( { command awk -v lts="${LTS-}" '{
         if (!$1) { next }
         if (lts && $10 ~ /^\-?$/) { next }
         if (lts && lts != "*" && tolower($10) !~ tolower(lts)) { next }
@@ -2732,7 +2737,7 @@ nvm_npm_global_modules() {
   local NPMLIST
   local VERSION
   VERSION="$1"
-  NPMLIST=$(nvm use "${VERSION}" >/dev/null && npm list -g --depth=0 2>/dev/null | command sed 1,1d | nvm_grep -v 'UNMET PEER DEPENDENCY')
+  NPMLIST=$(nvm use "${VERSION}" >/dev/null && npm list -g --depth=0 2>/dev/null | command sed -e '1d' -e '/UNMET PEER DEPENDENCY/d')
 
   local INSTALLS
   INSTALLS=$(nvm_echo "${NPMLIST}" | command sed -e '/ -> / d' -e '/\(empty\)/ d' -e 's/^.* \(.*@[^ ]*\).*/\1/' -e '/^npm@[^ ]*.*$/ d' | command xargs)