Now with better Bash 3.2 support!

It is possible to declare a variable but not assign a value to it using
`export x`. When you do this, `declare -p x` shows the variable but does
not show an "=" nor any value afterwards.

When running another command, this variable will not be added to the
environment variables even though it is flagged as exported. Most likely
it's because the value is not a string and can't be easily converted to
a string; this is the same behavior as arrays.

Using `[[ -v x ]]` is also inadequate and I believe its because there
are false positives when trying to access data, which goes on to break
tests and the new braces and parenthesis indirection. Perhaps it could
be reviewed and made to work.

The best solution so far is to combine `declare -p` with `[[ -v` to see
if the variable is declared and if a value is set.

Closes #75.

.github/workflows/release.yaml

@@ -20,7 +20,7 @@ jobs:
         uses: docker/setup-buildx-action@v1
       - name: Cache Docker layers
         if: startsWith(github.ref, 'refs/tags/')
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: /tmp/.buildx-cache
           key: ${{ runner.os }}-buildx-${{ github.sha }}

README.md

@@ -117,9 +117,11 @@ There are more scripts available in the [demos directory](demo/) that could help
 
 There are additional features that the program supports. Try using `mo --help` to see what is available.
 
+Please note that this command is written in Bash and pulls data from either the environment or (when using `--source`) from a text file that will be sourced and loaded into the environment, which means you will need to have Bash-style variables defined. Please see the examples in `demo/` for different ways you can use `mo`.
+
 
 Enhancements
------------
+------------
 
 In addition to many of the features built-in to Mustache, `mo` includes a number of unique features that make it a bit more powerful.
 
@@ -263,6 +265,7 @@ Pull requests to solve the following issues would be helpful.
 
 * Dotted names are supported but only for associative arrays (Bash 4).  See [`demo/associative-arrays`](demo/associative-arrays) for an example.
 * There's no "top level" object, so `echo '{{.}}' | ./mo` does not do anything useful.  In other languages you can say the data for the template is a string and in `mo` the data is always the environment.  Luckily this type of usage is rare and `{{.}}` works great when iterating over an array.
+* [Parents](https://mustache.github.io/mustache.5.html#Parents), where a template can override chunks of a partial, are not supported.
 * HTML encoding is not built into `mo`.  `{{{var}}}`, `{{&var}}` and `{{var}}` all do the same thing.  `echo '{{TEST}}' | TEST='<b>' mo` will give you "`<b>`" instead of "`&gt;b&lt;`".
 
 

mo

@@ -38,7 +38,8 @@
 #/          This message.
 #/    -s=FILE, --source=FILE
 #/          Load FILE into the environment before processing templates.
-#/          Can be used multiple times.
+#/          Can be used multiple times. The file must be a valid shell script
+#/          and should only contain variable assignments.
 #/    -o=DELIM, --open=DELIM
 #/          Set the opening delimiter. Default is "{{".
 #/    -c=DELIM, --close=DELIM
@@ -114,6 +115,8 @@ mo() (
     moDoubleHyphens=false
     MO_OPEN_DELIMITER_DEFAULT="{{"
     MO_CLOSE_DELIMITER_DEFAULT="}}"
+    MO_FUNCTION_CACHE_HIT=()
+    MO_FUNCTION_CACHE_MISS=()
 
     if [[ $# -gt 0 ]]; then
         for arg in "$@"; do
@@ -155,7 +158,7 @@ mo() (
                             moSource="${arg#-s=}"
                         fi
 
-                        if [[ -f "$moSource" ]]; then
+                        if [[ -e "$moSource" ]]; then
                             # shellcheck disable=SC1090
                             . "$moSource"
                         else
@@ -429,20 +432,19 @@ mo::indirectArray() {
 #
 # Returns nothing.
 mo::trimUnparsed() {
-    local moLast moR moN moT
+    local moI moC
 
-    moLast=""
-    moR=$'\r'
-    moN=$'\n'
-    moT=$'\t'
+    moI=0
+    moC=${MO_UNPARSED:0:1}
 
-    while [[ "$MO_UNPARSED" != "$moLast" ]]; do
-        moLast=$MO_UNPARSED
-        MO_UNPARSED=${MO_UNPARSED# }
-        MO_UNPARSED=${MO_UNPARSED#"$moR"}
-        MO_UNPARSED=${MO_UNPARSED#"$moN"}
-        MO_UNPARSED=${MO_UNPARSED#"$moT"}
+    while [[ "$moC" == " " || "$moC" == $'\r' || "$moC" == $'\n' || "$moC" == $'\t' ]]; do
+        moI=$((moI + 1))
+        moC=${MO_UNPARSED:$moI:1}
     done
+
+    if [[ "$moI" != 0 ]]; then
+        MO_UNPARSED=${MO_UNPARSED:$moI}
+    fi
 }
 
 
@@ -900,10 +902,42 @@ mo::parseValue() {
 #
 # Returns 0 if the name is a function, 1 otherwise.
 mo::isFunction() {
+    local moFunctionName
+
+    # Need to test for the array length, otherwise Mac will report an
+    # unbound variable
+    if [[ "${#MO_FUNCTION_CACHE_HIT[@]}" -gt 0 ]]; then
+        for moFunctionName in "${MO_FUNCTION_CACHE_HIT[@]}"; do
+            if [[ "$moFunctionName" == "$1" ]]; then
+                return 0
+            fi
+        done
+    fi
+
+    if [[ "${#MO_FUNCTION_CACHE_MISS[@]}" -gt 0 ]]; then
+        for moFunctionName in "${MO_FUNCTION_CACHE_MISS[@]}"; do
+            if [[ "$moFunctionName" == "$1" ]]; then
+                return 1
+            fi
+        done
+    fi
+
     if declare -F "$1" &> /dev/null; then
+        if [[ "${#MO_FUNCTION_CACHE_HIT[@]}" -gt 0 ]]; then
+            MO_FUNCTION_CACHE_HIT=( ${MO_FUNCTION_CACHE_HIT[@]+"${MO_FUNCTION_CACHE_HIT[@]}"} "$1" )
+        else
+            MO_FUNCTION_CACHE_HIT=( "$1" )
+        fi
+
         return 0
     fi
 
+    if [[ "${#MO_FUNCTION_CACHE_MISS[@]}" -gt 0 ]]; then
+        MO_FUNCTION_CACHE_MISS=( ${MO_FUNCTION_CACHE_MISS[@]+"${MO_FUNCTION_CACHE_MISS[@]}"} "$1" )
+    else
+        MO_FUNCTION_CACHE_MISS=( "$1" )
+    fi
+
     return 1
 }
 
@@ -982,14 +1016,50 @@ mo::isArrayIndexValid() {
 # Can not use logic like this in case invalid variable names are passed.
 #     [[ "${!1-a}" == "${!1-b}" ]]
 #
+# Using logic like this gives false positives. Also, this is not supported on
+# Bash 3.2 and the script parsing will error before any commands are executed.
+#     [[ -v "$a" ]]
+#
+# Declaring a variable is not the same as assigning the variable.
+#     export x
+#     declare -p x   # Output: declare -x x
+#                    # Bash 3.2 returns error code 1 and outputs:
+#                    # bash: declare: x: not found
+#     export y=""
+#     declare -p y   # Output: declare -x y=""
+#     unset z
+#     declare -p z   # Error code 1 and output: bash: declare: z: not found
+#
 # Returns true (0) if the variable is set, 1 if the variable is unset.
-mo::isVarSet() {
-    if ! declare -p "$1" &> /dev/null; then
-        return 1
-    fi
+MO_VAR_TEST="ok"
 
-    return 0
-}
+# This must not use `[[` because otherwise Bash 3.2 will stop execution and
+# always write to stderr without the ability to capture it.
+if test -v "MO_VAR_TEST" &> /dev/null; then
+    mo::debug "Using declare -p and [[ -v ]] for variable checks"
+    # More recent Bash
+    mo::isVarSet() {
+        # Do not convert this to [[, otherwise Bash 3.2 will fail to parse the
+        # script.
+        if declare -p "$1" &> /dev/null && test -v "$1"; then
+            return 0
+        fi
+
+        return 1
+    }
+else
+    mo::debug "Using declare -p for variable checks"
+    # Bash 3.2
+    mo::isVarSet() {
+        # If the variable is exported and not assigned, declare -p will error.
+        if declare -p "$1" &> /dev/null; then
+            return 0
+        fi
+
+        return 1
+    }
+fi
+unset MO_VAR_TEST
 
 
 # Internal: Determine if a value is considered truthy.
@@ -1399,31 +1469,40 @@ mo::standaloneCheck() {
 #
 # Returns nothing.
 mo::standaloneProcess() {
-    local moContent moLast moT moR moN
-
-    moT=$'\t'
-    moR=$'\r'
-    moN=$'\n'
-    moLast=
+    local moI moTemp
 
     mo::debug "Standalone tag - processing content before and after tag"
+    moI=$((${#MO_PARSED} - 1))
+    mo::debug "zero done ${#MO_PARSED}"
+    mo::escape moTemp "$MO_PARSED"
+    mo::debug "$moTemp"
 
-    while [[ "$moLast" != "$MO_PARSED" ]]; do
-        moLast=$MO_PARSED
-        MO_PARSED=${MO_PARSED% }
-        MO_PARSED=${MO_PARSED%"$moT"}
+    # Mac appears to allow getting characters from before the start of the string
+    while [[ "$moI" -ge 0 ]] && [[ "${MO_PARSED:$moI:1}" == " " || "${MO_PARSED:$moI:1}" == $'\t' ]]; do
+        moI=$((moI - 1))
     done
 
-    moLast=
+    if [[ $((moI + 1)) != "${#MO_PARSED}" ]]; then
+        MO_PARSED="${MO_PARSED:0:${moI}+1}"
+    fi
 
-    while [[ "$moLast" != "$MO_UNPARSED" ]]; do
-        moLast=$MO_UNPARSED
-        MO_UNPARSED=${MO_UNPARSED# }
-        MO_UNPARSED=${MO_UNPARSED#"$moT"}
+    moI=0
+
+    while [[ "${MO_UNPARSED:${moI}:1}" == " " || "${MO_UNPARSED:${moI}:1}" == $'\t' ]]; do
+        moI=$((moI + 1))
     done
 
-    MO_UNPARSED=${MO_UNPARSED#"$moR"}
-    MO_UNPARSED=${MO_UNPARSED#"$moN"}
+    if [[ "${MO_UNPARSED:${moI}:1}" == $'\r' ]]; then
+        moI=$((moI + 1))
+    fi
+
+    if [[ "${MO_UNPARSED:${moI}:1}" == $'\n' ]]; then
+        moI=$((moI + 1))
+    fi
+
+    if [[ "$moI" != 0 ]]; then
+        MO_UNPARSED=${MO_UNPARSED:${moI}}
+    fi
 }
 
 
@@ -1949,7 +2028,7 @@ mo::tokenizeTagContentsSingleQuote() {
 
 # Save the original command's path for usage later
 MO_ORIGINAL_COMMAND="$(cd "${BASH_SOURCE[0]%/*}" || exit 1; pwd)/${BASH_SOURCE[0]##*/}"
-MO_VERSION="3.0.2"
+MO_VERSION="3.1.0"
 
 # If sourced, load all functions.
 # If executed, perform the actions as expected.

tests/help

@@ -43,7 +43,8 @@ Options:
          This message.
    -s=FILE, --source=FILE
          Load FILE into the environment before processing templates.
-         Can be used multiple times.
+         Can be used multiple times. The file must be a valid shell script
+         and should only contain variable assignments.
    -o=DELIM, --open=DELIM
          Set the opening delimiter. Default is "{{".
    -c=DELIM, --close=DELIM
@@ -93,7 +94,7 @@ This is open source!  Please feel free to contribute.
 
 https://github.com/tests-always-included/mo
 
-MO_VERSION=3.0.2
+MO_VERSION=3.0.7
 EOF
 }
 

tests/issue-75

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+cd "${0%/*}" || exit 1
+. ../run-tests
+
+export uv
+export template='{{^uv}}OK{{/uv}}{{#uv}}FAIL{{/uv}}'
+export expected='OK'
+
+runTest