From 8ba9823407d4c177497f765379bd76f3d83f74ae Mon Sep 17 00:00:00 2001 From: Erik Flodin Date: Sun, 27 Oct 2024 13:38:12 +0100 Subject: [PATCH] Rewrite default template to handle nested ifs, != and env vars in if The awk script now performs all processing in the BEGIN block using an implementation that is capable of handling if statements which contain nested if statments (fixes #436). To make nested ifs look better, if, else and endif lines can now have optional whitespace before {%. Includes are now handled in the same way as the main file which means that included files can both include other files and have if statements in addition to variables (fixes #406). Include lines can now also have optional whitespace before {%. All variables are handled in the same way now so it's now possible to use env variables in if statements (fixes #488). Also add support for != in addition to == (fixes #358). Thus it's now e.g. possible to check if a variable is set (#477) by doing: {% if yadm.class != ""%} Class is set to {{ yadm.class }} {% endif %} A non-existing yadm or env variable is now replaced with the empty string. --- test/test_unit_template_default.py | 75 ++++++++++++- yadm | 169 ++++++++++++++++------------- 2 files changed, 168 insertions(+), 76 deletions(-) diff --git a/test/test_unit_template_default.py b/test/test_unit_template_default.py index 7243877..aaae0fe 100644 --- a/test/test_unit_template_default.py +++ b/test/test_unit_template_default.py @@ -1,4 +1,5 @@ """Unit tests: template_default""" + import os FILE_MODE = 0o754 @@ -12,6 +13,7 @@ LOCAL_HOST = "default_Test+@-!^Host" LOCAL_USER = "default_Test+@-!^User" LOCAL_DISTRO = "default_Test+@-!^Distro" LOCAL_DISTRO_FAMILY = "default_Test+@-!^Family" +ENV_VAR = "default_Test+@-!^Env" TEMPLATE = f""" start of template default class = >{{{{yadm.class}}}}< @@ -30,6 +32,9 @@ Included section from else {{% if yadm.class == "wrongclass1" %}} wrong class 1 {{% endif %}} +{{% if yadm.class != "wronglcass" %}} +Included section from != +{{% endif\t\t %}} {{% if yadm.class == "{LOCAL_CLASS}" %}} Included section for class = {{{{yadm.class}}}} ({{{{yadm.class}}}} repeated) Multiple lines @@ -97,6 +102,13 @@ Included section for distro_family = \ {{% if yadm.distro_family == "wrongfamily2" %}} wrong family 2 {{% endif %}} +{{% if env.VAR == "{ENV_VAR}" %}} +Included section for env.VAR = {{{{env.VAR}}}} ({{{{env.VAR}}}} again) +{{% endif %}} +{{% if env.VAR == "wrongenvvar" %}} +wrong env.VAR +{{% endif %}} +yadm.no_such_var="{{{{ yadm.no_such_var }}}}" and env.NO_SUCH_VAR="{{{{ env.NO_SUCH_VAR }}}}" end of template """ EXPECTED = f""" @@ -111,6 +123,7 @@ default distro_family = >{LOCAL_DISTRO_FAMILY}< classes = >{LOCAL_CLASS2} {LOCAL_CLASS}< Included section from else +Included section from != Included section for class = {LOCAL_CLASS} ({LOCAL_CLASS} repeated) Multiple lines Included section for second class @@ -121,6 +134,8 @@ Included section for user = {LOCAL_USER} ({LOCAL_USER} repeated) Included section for distro = {LOCAL_DISTRO} ({LOCAL_DISTRO} again) Included section for distro_family = \ {LOCAL_DISTRO_FAMILY} ({LOCAL_DISTRO_FAMILY} again) +Included section for env.VAR = {ENV_VAR} ({ENV_VAR} again) +yadm.no_such_var="" and env.NO_SUCH_VAR="" end of template """ @@ -138,7 +153,7 @@ The first line An empty file removes the line above {%include basic%} {% include "./variables.{{ yadm.os }}" %} -{% include dir/nested %} + {% include dir/nested %} Include basic again: {% include basic %} """ @@ -154,6 +169,42 @@ Include basic again: basic """ +TEMPLATE_NESTED_IFS = """\ +{% if yadm.user == "me" %} + print1 + {% if yadm.user == "me" %} + print2 + {% else %} + no print1 + {% endif %} +{% else %} + {% if yadm.user == "me" %} + no print2 + {% else %} + no print3 + {% endif %} +{% endif %} +{% if yadm.user != "me" %} + no print4 + {% if yadm.user == "me" %} + no print5 + {% else %} + no print6 + {% endif %} +{% else %} + {% if yadm.user == "me" %} + print3 + {% else %} + no print7 + {% endif %} +{% endif %} +""" +EXPECTED_NESTED_IFS = """\ + print1 + print2 + print3 +""" + def test_template_default(runner, yadm, tmpdir): """Test template_default""" @@ -182,7 +233,7 @@ def test_template_default(runner, yadm, tmpdir): local_distro_family="{LOCAL_DISTRO_FAMILY}" template_default "{input_file}" "{output_file}" """ - run = runner(command=["bash"], inp=script) + run = runner(command=["bash"], inp=script, env={"VAR": ENV_VAR}) assert run.success assert run.err == "" assert output_file.read() == EXPECTED @@ -243,12 +294,30 @@ def test_include(runner, yadm, tmpdir): assert os.stat(output_file).st_mode == os.stat(input_file).st_mode +def test_nested_ifs(runner, yadm, tmpdir): + """Test nested if statements""" + + input_file = tmpdir.join("input") + input_file.write(TEMPLATE_NESTED_IFS, ensure=True) + output_file = tmpdir.join("output") + + script = f""" + YADM_TEST=1 source {yadm} + set_awk + local_user="me" + template_default "{input_file}" "{output_file}" + """ + run = runner(command=["bash"], inp=script) + assert run.success + assert run.err == "" + assert output_file.read() == EXPECTED_NESTED_IFS + + def test_env(runner, yadm, tmpdir): """Test env""" input_file = tmpdir.join("input") input_file.write("{{env.PWD}}", ensure=True) - input_file.chmod(FILE_MODE) output_file = tmpdir.join("output") script = f""" diff --git a/yadm b/yadm index 09da278..9dc9240 100755 --- a/yadm +++ b/yadm @@ -368,87 +368,110 @@ function template_default() { # the explicit "space + tab" character class used below is used because not # all versions of awk seem to support the POSIX character classes [[:blank:]] read -r -d '' awk_pgm << "EOF" -# built-in default template processor BEGIN { - blank = "[ ]" - c["class"] = class - c["classes"] = classes - c["arch"] = arch - c["os"] = os - c["hostname"] = host - c["user"] = user - c["distro"] = distro - c["distro_family"] = distro_family - c["source"] = source - ifs = "^{%" blank "*if" - els = "^{%" blank "*else" blank "*%}$" - end = "^{%" blank "*endif" blank "*%}$" - skp = "^{%" blank "*(if|else|endif)" - vld = conditions() - inc_start = "^{%" blank "*include" blank "+\"?" - inc_end = "\"?" blank "*%}$" - inc = inc_start ".+" inc_end - prt = 1 - err = 0 -} -END { exit err } -{ replace_vars() } # variable replacements -$0 ~ vld, $0 ~ end { - if ($0 ~ vld || $0 ~ end) prt=1; - if ($0 ~ els) prt=0; - if ($0 ~ skp) next; -} -($0 ~ ifs && $0 !~ vld), $0 ~ end { - if ($0 ~ ifs && $0 !~ vld) prt=0; - if ($0 ~ els || $0 ~ end) prt=1; - if ($0 ~ skp) next; -} -{ if (!prt) next } -$0 ~ inc { - file = $0 - sub(inc_start, "", file) - sub(inc_end, "", file) - sub(/^[^\/].*$/, source_dir "/&", file) + yadm["class"] = class + yadm["classes"] = classes + yadm["arch"] = arch + yadm["os"] = os + yadm["hostname"] = host + yadm["user"] = user + yadm["distro"] = distro + yadm["distro_family"] = distro_family + yadm["source"] = source - while ((res = getline 0) { - replace_vars() - print + VARIABLE = "(env|yadm)\\.[a-zA-Z0-9_]+" + + current = 0 + filename[current] = ARGV[1] + line[current] = 0 + + level = 0 + skip[level] = 0 + + for (; current >= 0; --current) { + while ((res = getline 0) { + ++line[current] + if ($0 ~ "^[ \t]*\\{%[ \t]*if[ \t]+" VARIABLE "[ \t]*[!=]=[ \t]*\".*\"[ \t]*%\\}$") { + if (skip[level]) { skip[++level] = 1; continue } + + match($0, VARIABLE) + lhs = substr($0, RSTART, RLENGTH) + match($0, /[!=]=/) + op = substr($0, RSTART, RLENGTH) + match($0, /".*"/) + rhs = replace_vars(substr($0, RSTART + 1, RLENGTH - 2)) + + if (lhs == "yadm.class") { + lhs = "not" rhs + split(classes, cls_array, "\n") + for (idx in cls_array) { + if (rhs == cls_array[idx]) { lhs = rhs; break } + } + } + else { + lhs = replace_vars("{{" lhs "}}") + } + + if (op == "==") { skip[++level] = lhs != rhs } + else { skip[++level] = lhs == rhs } + } + else if (/^[ \t]*\{%[ \t]*else[ \t]*%\}$/) { + if (level == 0 || skip[level] < 0) { error("else without matching if") } + skip[level] = skip[level] ? skip[level - 1] : -1 + } + else if (/^[ \t]*\{%[ \t]*endif[ \t]*%\}$/) { + if (--level < 0) { error("endif without matching if") } + } + else if (!skip[level]) { + $0 = replace_vars($0) + if (match($0, /^[ \t]*\{%[ \t]*include[ \t]+("[^"]+"|[^"]+)[ \t]*%\}$/)) { + include = $0 + sub(/^[ \t]*\{%[ \t]*include[ \t]+"?/, "", include) + sub(/"?[ \t]*%\}$/, "", include) + if (index(include, "/") != 1) { + include = source_dir "/" include + } + filename[++current] = include + line[current] = 0 + } + else { print } + } + } + if (res >= 0) { close(filename[current]) } + else if (current == 0) { error("could not read input file") } + else { --current; error("could not read include file '" filename[current + 1] "'") } } - if (res < 0) { - printf "%s:%d: error: could not read '%s'\n", FILENAME, NR, file | "cat 1>&2" - err = 1 + if (level > 0) { + current = 0 + error("unterminated if") } - close(file) - next + exit 0 } -{ print } -function replace_vars() { - for (label in c) { - gsub(("{{" blank "*yadm\\." label blank "*}}"), c[label]) - } - for (label in ENVIRON) { - gsub(("{{" blank "*env\\." label blank "*}}"), ENVIRON[label]) - } +function error(text) { + printf "%s:%d: error: %s\n", + filename[current], line[current], text > "/dev/stderr" + exit 1 } -function condition_helper(label, value) { - gsub(/[\\.^$(){}\[\]|*+?]/, "\\\\&", value) - return sprintf("yadm\\.%s" blank "*==" blank "*\"%s\"", label, value) -} -function conditions() { - pattern = ifs blank "+(" - for (label in c) { - if (label != "class") { - value = c[label] - pattern = sprintf("%s%s|", pattern, condition_helper(label, value)); +function replace_vars(input) { + output = "" + while (match(input, "\\{\\{[ \t]*" VARIABLE "[ \t]*\\}\\}")) { + if (RSTART > 1) { + output = output substr(input, 0, RSTART - 1) + } + data = substr(input, RSTART + 2, RLENGTH - 4) + input = substr(input, RSTART + RLENGTH) + + gsub(/[ \t]+/, "", data) + split(data, fields, /\./) + + if (fields[1] == "env") { + output = output ENVIRON[fields[2]] + } + else { + output = output yadm[fields[2]] } } - split(classes, cls_array, "\n") - for (idx in cls_array) { - value = cls_array[idx] - pattern = sprintf("%s%s|", pattern, condition_helper("class", value)); - } - sub(/\|$/, ")" blank "*%}$", pattern) - return pattern + return output input } EOF