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-rw-r--r--tests/aux/json.sh402
-rw-r--r--tests/local.mk3
2 files changed, 404 insertions, 1 deletions
diff --git a/tests/aux/json.sh b/tests/aux/json.sh
new file mode 100644
index 0000000..8f2cf9d
--- /dev/null
+++ b/tests/aux/json.sh
@@ -0,0 +1,402 @@
+# `json.sh`, a pure-shell JSON parser.
+#
+# Copied from <lib/json.sh> in repository <https://github.com/rcrowley/json.sh>.
+#
+# Copyright 2011 Richard Crowley. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following
+# disclaimer in the documentation and/or other materials provided
+# with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY RICHARD CROWLEY AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL RICHARD CROWLEY OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+# THE POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and documentation
+# are those of the authors and should not be interpreted as representing
+# official policies, either expressed or implied, of Richard Crowley.
+
+set -e
+
+# Most users will be happy with the default '/' separator that makes trees
+# of keys look like filesystem paths but that breaks down if keys can
+# contain slashes. In that case, set `JSON_SEPARATOR` to desired character.
+[ -z "$JSON_SEPARATOR" ] && _J_S="/" || _J_S="$JSON_SEPARATOR"
+
+# File descriptor 3 is commandeered for debug output, which may end up being
+# forwarded to standard error.
+[ -z "$JSON_DEBUG" ] && exec 3>/dev/null || exec 3>&2
+
+# File descriptor 4 is commandeered for use as a sink for literal and
+# variable output of (inverted) sections that are not destined for standard
+# output because their condition is not met.
+exec 4>/dev/null
+
+# Consume standard input one character at a time to parse JSON.
+json() {
+
+ # Initialize the file descriptor to be used to emit characters. At
+ # times this value will be 4 to send output to `/dev/null`.
+ _J_FD=1
+
+ # Initialize storage for the "pathname", the concatenation of all
+ # the keys in the tree at any point in time, the current state of
+ # the machine, and the state to which the machine returns after
+ # completing a key or value.
+ _J_PATHNAME="$_J_S" _J_STATE="whitespace" _J_STATE_DEFAULT="whitespace"
+
+ # IFS must only contain '\n' so as to be able to read space and tab
+ # characters from standard input one-at-a-time. The easiest way to
+ # convince it to actually contain the correct byte, and only the
+ # correct byte, is to use a single-quoted literal newline.
+ IFS='
+'
+
+ # Consuming standard input one character at a time is quite a feat
+ # within the confines of POSIX shell. Bash's `read` builtin has
+ # `-n` for limiting the number of characters consumed. Here it is
+ # faked using `sed`(1) to place each character on its own line.
+ # The subtlety is that real newline characters are chomped so they
+ # must be indirectly detected by checking for zero-length
+ # characters, which is done as the character is emitted.
+ sed "
+ s/./&$(printf "\036")/g
+ s/\\\\/\\\\\\\\/g
+ " | tr "\036" "\n" | _json
+
+ # TODO Replace the original value of IFS. Be careful if it's unset.
+
+}
+
+# Consume the one-character-per-line stream from `sed` via a state machine.
+# This function will be called recursively in subshell environments to
+# isolate values from their containing scope.
+#
+# The `read` builtin consumes one line at a time but by now each line
+# contains only a single character.
+_json() {
+ while read _J_C
+ do
+ _json_char
+ _J_PREV_C="$_J_C"
+ done
+}
+
+# Consume a single character as stored in `_J_C`. This function is broken
+# out from `_json` so it may be called to reconsume a character as is
+# necessary following the end of any number since numbers do not have a
+# well-known ending in the grammar.
+#
+# The state machine implemented here follows very naturally from the
+# diagrams of the JSON grammar on <http://json.org>.
+_json_char() {
+ echo " _J_C: $_J_C (${#_J_C}), _J_STATE: $_J_STATE" >&3
+ case "$_J_STATE" in
+
+ # The machine starts in the "whitespace" state and learns
+ # from leading characters what state to enter next. JSON's
+ # grammar doesn't contain any tokens that are ambiguous in
+ # their first character so the parser's job is relatively
+ # easier.
+ #
+ # Further whitespace characters are consumed and ignored.
+ #
+ # Arrays are unique in that their parsing rules are a strict
+ # superset of the rules in open whitespace. When an opening
+ # bracket is encountered, the remainder of the array is
+ # parsed in a subshell which goes around again when a comma
+ # is encountered and exits back to the containing scope when
+ # the closing bracket is encountered.
+ #
+ # Objects are not parsed as a superset of open whitespace but
+ # they are parsed in a subshell to protect the containing scope.
+ "array-0"|"array-even"|"array-odd"|"whitespace")
+ case "$_J_STATE" in
+ "array-0")
+ case "$_J_C" in
+ "]") exit;;
+ esac;;
+ "array-even")
+ case "$_J_C" in
+ ",")
+ _J_DIRNAME="${_J_PATHNAME%"$_J_S"*}"
+ [ "$_J_DIRNAME" = "$_J_S" ] && _J_DIRNAME=""
+ _J_BASENAME="${_J_PATHNAME##*"$_J_S"}"
+ _J_BASENAME="$(($_J_BASENAME + 1))"
+ _J_PATHNAME="$_J_DIRNAME$_J_S$_J_BASENAME"
+ _J_STATE="array-odd"
+ continue;;
+ "]") exit;;
+ esac;;
+ esac
+ case "$_J_C" in
+ "\"") _J_STATE="string" _J_V="";;
+ "-") _J_STATE="number-negative" _J_V="$_J_C";;
+ 0) _J_STATE="number-leading-zero" _J_V="$_J_C";;
+ [1-9]) _J_STATE="number-leading-nonzero" _J_V="$_J_C";;
+ "[")
+ (
+ [ "$_J_PATHNAME" = "/" ] && _J_PATHNAME=""
+ _J_PATHNAME="$_J_PATHNAME/0"
+ _J_STATE="array-0" _J_STATE_DEFAULT="array-even"
+ _json
+ )
+ _J_STATE="$_J_STATE_DEFAULT" _J_V="";;
+ "f"|"t") _J_STATE="boolean" _J_V="$_J_C";;
+ "n") _J_STATE="null" _J_V="$_J_C";;
+ "{")
+ (
+ _J_STATE="object-0" _J_STATE_DEFAULT="object-even"
+ _json
+ )
+ _J_STATE="$_J_STATE_DEFAULT" _J_V="";;
+ " "|""|" ") ;;
+ *) _json_die "syntax: $_J_PATHNAME";;
+ esac;;
+
+ # Boolean values are multicharacter literals but they're unique
+ # from their first character. This means the eventual value is
+ # already known when the "boolean" state is entered so we can
+ # raise syntax errors as soon as the input goes south.
+ "boolean")
+ case "$_J_V$_J_C" in
+ "f"|"fa"|"fal"|"fals"|"t"|"tr"|"tru") _J_V="$_J_V$_J_C";;
+ "false"|"true")
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME boolean $_J_V$_J_C" >&$_J_FD;;
+ *) _json_die "syntax: $_J_PATHNAME boolean $_J_V$_J_C";;
+ esac;;
+
+ # Object values are relatively more complex than array values.
+ # They begin in the "object-0" state, which is almost but not
+ # quite a subset of the "whitespace" state for strings. When
+ # a string is encountered it is parsed as usual but the parser
+ # is set to return to the "object-value" state afterward.
+ #
+ # As in the "whitespace" state, extra whitespace characters
+ # are consumed and ignored.
+ #
+ # The parser will return to this "object" state later to
+ # either consume a comma and go around again or exit the
+ # subshell in which this object has been parsed.
+ "object-0")
+ case "$_J_C" in
+ "\"")
+ _J_FD=4
+ _J_STATE="string"
+ _J_STATE_DEFAULT="object-value"
+ _J_V="";;
+ "}") exit;;
+ " "|""|" ") ;;
+ *) _json_die "syntax: $_J_PATHNAME";;
+ esac;;
+
+ # "object-even" is like "object-0" but additionally commas are
+ # consumed to enforce the another key/value pair is coming.
+ "object-even")
+ case "$_J_C" in
+ "\"")
+ _J_FD=4
+ _J_STATE="string"
+ _J_STATE_DEFAULT="object-value"
+ _J_V="";;
+ ",") _J_STATE="object-odd";;
+ "}") exit;;
+ " "|""|" ") ;;
+ *) _json_die "syntax: $_J_PATHNAME";;
+ esac;;
+
+ # Object values have to return from whence they came. They use
+ # the "object-exit" state to signal the last character consumed
+ # to the containing scope.
+ "object-exit") #exit;;
+ case "$_J_C" in
+ ",") exit 101;;
+ "}") exit 102;;
+ *) exit 0;;
+ esac;;
+
+ # "object-even" is like "object-0" but cannot consume a closing
+ # brace because it has just consumed a comma.
+ "object-odd")
+ case "$_J_C" in
+ "\"")
+ _J_FD=4
+ _J_STATE="string"
+ _J_STATE_DEFAULT="object-value"
+ _J_V="";;
+ " "|""|" ") ;;
+ *) _json_die "syntax: $_J_PATHNAME";;
+ esac;;
+
+ # After a string key has been consumed, the state machine
+ # progresses here where a colon and a value are parsed. The
+ # value is parsed in a subshell so the pathname can have the
+ # key appended to it before the parser continues.
+ "object-value")
+ case "$_J_C" in
+ ":")
+ _J_FD=1
+ (
+ [ "$_J_PATHNAME" = "/" ] && _J_PATHNAME=""
+ _J_PATHNAME="$_J_PATHNAME/$_J_V"
+ _J_STATE="whitespace"
+ _J_STATE_DEFAULT="object-exit"
+ _json
+ ) || case "$?" in
+ 101) _J_STATE="object-even" _J_C="," _json_char;;
+ 102) _J_STATE="object-even" _J_C="}" _json_char;;
+ esac
+ _J_STATE="object-even";;
+ " "|""|" ") ;;
+ *) _json_die "syntax: $_J_PATHNAME";;
+ esac;;
+
+ # Null values work exactly like boolean values. See above.
+ "null")
+ case "$_J_V$_J_C" in
+ "n"|"nu"|"nul") _J_V="$_J_V$_J_C";;
+ "null")
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME null null" >&$_J_FD;;
+ *) _json_die "syntax: $_J_PATHNAME null $_J_V$_J_C";;
+ esac;;
+
+ # Numbers that encounter a '.' become floating point and may
+ # continue consuming digits forever or may become
+ # scientific-notation. Any other character sends the parser
+ # back to its default state.
+ "number-float")
+ case "$_J_C" in
+ [0-9]) _J_V="$_J_V$_J_C";;
+ "E"|"e") _J_STATE="number-sci" _J_V="$_J_V$_J_C";;
+ *)
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME number $_J_V" >&$_J_FD
+ _json_char;;
+ esac;;
+
+ # This is an entrypoint into parsing a number, used when
+ # the first digit consumed is non-zero. From here, a number
+ # may continue on a positive integer, become a floating-point
+ # number by consuming a '.', or become scientific-notation by
+ # consuming an 'E' or 'e'. Any other character sends the
+ # parser back to its default state.
+ "number-leading-nonzero")
+ case "$_J_C" in
+ ".") _J_STATE="number-float" _J_V="$_J_V$_J_C";;
+ [0-9]) _J_V="$_J_V$_J_C";;
+ "E"|"e") _J_STATE="number-sci" _J_V="$_J_V$_J_C";;
+ *)
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME number $_J_V" >&$_J_FD
+ _json_char;;
+ esac;;
+
+ # This is an entrypoint into parsing a number, used when
+ # the first digit consumed is zero. From here, a number
+ # may remain zero, become a floating-point number by
+ # consuming a '.', or become scientific-notation by consuming
+ # an 'E' or 'e'. Any other character sends the parser back
+ # to its default state.
+ "number-leading-zero")
+ case "$_J_C" in
+ ".") _J_STATE="number-float" _J_V="$_J_V$_J_C";;
+ [0-9]) _json_die "syntax: $_J_PATHNAME number $_J_V$_J_C";;
+ "E"|"e") _J_STATE="number-sci" _J_V="$_J_V$_J_C";;
+ *)
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME number $_J_V" >&$_J_FD
+ _json_char;;
+ esac;;
+
+ # This is an entrypoint into parsing a number, used when
+ # the first character consumed is a '-'. From here, a number
+ # may progress to the "number-leading-nonzero" or
+ # "number-leading-zero" states. Any other character sends
+ # the parser back to its default state.
+ "number-negative")
+ case "$_J_C" in
+ 0) _J_STATE="number-leading-zero" _J_V="$_J_V$_J_C";;
+ [1-9])
+ _J_STATE="number-leading-nonzero"
+ _J_V="$_J_V$_J_C";;
+ *)
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME number $_J_V" >&$_J_FD
+ _json_char;;
+ esac;;
+
+ # Numbers that encounter an 'E' or 'e' become
+ # scientific-notation and consume digits, optionally prefixed
+ # by a '+' or '-', forever. The actual consumption is
+ # delegated to the "number-sci-neg" and "number-sci-pos"
+ # states. Any other character immediately following the 'E'
+ # or 'e' is a syntax error.
+ "number-sci")
+ case "$_J_C" in
+ "+") _J_STATE="number-sci-pos" _J_V="$_J_V$_J_C";;
+ "-") _J_STATE="number-sci-neg" _J_V="$_J_V$_J_C";;
+ [0-9]) _J_STATE="number-sci-pos" _J_V="$_J_V$_J_C";;
+ *) _json_die "syntax: $_J_PATHNAME number $_J_V$_J_C";;
+ esac;;
+
+ # Once in these states, numbers may consume digits forever.
+ # Any other character sends the parser back to its default
+ # state.
+ "number-sci-neg"|"number-sci-pos")
+ case "$_J_C" in
+ [0-9]) _J_V="$_J_V$_J_C";;
+ *)
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME number $_J_V" >&$_J_FD
+ _json_char;;
+ esac;;
+
+ # Strings aren't as easy as they look. JSON supports several
+ # escape sequences that require the state machine to keep a
+ # history of its input. Basic backslash/newline/etc. escapes
+ # are simple because they only require one character of
+ # history. Unicode codepoint escapes require more. The
+ # strategy there is to add states to the machine.
+ #
+ # TODO It'd be nice to decode all escape sequences, including
+ # Unicode codepoints but that would definitely ruin the
+ # line-oriented thing we've got goin' on.
+ "string")
+ case "$_J_PREV_C$_J_C" in
+ "\\\""|"\\/"|"\\\\") _J_V="$_J_V$_J_C";;
+ "\\b"|"\\f"|"\\n"|"\\r") _J_V="$_J_V\\\\$_J_C";;
+ "\\u") _J_V="$_J_V\\\\$_J_C";;
+ *"\"")
+ _J_STATE="$_J_STATE_DEFAULT"
+ echo "$_J_PATHNAME string $_J_V" >&$_J_FD;;
+ *"\\") ;;
+ *) _J_V="$_J_V$_J_C";;
+ esac;;
+
+ esac
+}
+
+# Print an error message and GTFO. The message is the concatenation
+# of all the arguments to this function.
+_json_die() {
+ echo "json.sh: $*" >&2
+ exit 1
+}
diff --git a/tests/local.mk b/tests/local.mk
index 6d7980c..288b9ad 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -9,4 +9,5 @@ SH_LOG_DRIVER = \
EXTRA_DIST += \
$(TESTS) \
build-aux/tap-driver.sh \
- tests/aux/tap-functions.sh
+ tests/aux/tap-functions.sh \
+ tests/aux/json.sh