diff --git a/tests/test_helpers.d/ynhtest_config.sh b/tests/test_helpers.d/ynhtest_config.sh
new file mode 100644
index 000000000..69e715229
--- /dev/null
+++ b/tests/test_helpers.d/ynhtest_config.sh
@@ -0,0 +1,394 @@
+_make_dummy_files() {
+
+    local_dummy_dir="$1"
+
+    cat << EOF > $dummy_dir/dummy.ini
+# Some comment
+foo =
+enabled =    False
+# title = Old title
+title =    Lorem Ipsum
+email = root@example.com
+theme = colib'ris
+  port =     1234
+url = https://yunohost.org
+[dict]
+    ldap_base = ou=users,dc=yunohost,dc=org
+EOF
+
+    cat << EOF > $dummy_dir/dummy.py
+# Some comment
+FOO = None
+ENABLED = False
+# TITLE = "Old title"
+TITLE = "Lorem Ipsum"
+THEME = "colib'ris"
+EMAIL = "root@example.com"
+PORT   = 1234
+URL = 'https://yunohost.org'
+DICT['ldap_base'] = "ou=users,dc=yunohost,dc=org"
+EOF
+
+}
+
+_ynh_read_yaml_with_python() {
+    local file="$1"
+    local key="$2"
+    python3 -c "import yaml; print(yaml.safe_load(open('$file'))['$key'])"
+}
+
+_ynh_read_json_with_python() {
+    local file="$1"
+    local key="$2"
+    python3 -c "import json; print(json.load(open('$file'))['$key'])"
+}
+
+_ynh_read_php_with_php() {
+    local file="$1"
+    local key="$2"
+    php -r "include '$file'; echo var_export(\$$key);" | sed "s/^'//g" | sed "s/'$//g"
+}
+
+
+ynhtest_config_read_yaml() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.yml"
+
+    cat << EOF > $file
+# Some comment
+foo:
+enabled: false
+# title: old title
+title: Lorem Ipsum
+theme: colib'ris
+email: root@example.com
+port: 1234
+url: https://yunohost.org
+dict:
+   ldap_base: ou=users,dc=yunohost,dc=org
+EOF
+
+    test "$(_ynh_read_yaml_with_python "$file" "foo")" == "None"
+    test "$(ynh_read_var_in_file       "$file" "foo")" == ""
+    
+    test "$(_ynh_read_yaml_with_python "$file" "enabled")" == "False"
+    test "$(ynh_read_var_in_file       "$file" "enabled")" == "false"
+    
+    test "$(_ynh_read_yaml_with_python "$file" "title")" == "Lorem Ipsum"
+    test "$(ynh_read_var_in_file       "$file" "title")" == "Lorem Ipsum"
+    
+    test "$(_ynh_read_yaml_with_python "$file" "theme")" == "colib'ris"
+    test "$(ynh_read_var_in_file       "$file" "theme")" == "colib'ris"
+    
+    test "$(_ynh_read_yaml_with_python "$file" "email")" == "root@example.com"
+    test "$(ynh_read_var_in_file       "$file" "email")" == "root@example.com"
+    
+    test "$(_ynh_read_yaml_with_python "$file" "port")" == "1234"
+    test "$(ynh_read_var_in_file       "$file" "port")" == "1234"
+    
+    test "$(_ynh_read_yaml_with_python "$file" "url")" == "https://yunohost.org"
+    test "$(ynh_read_var_in_file       "$file" "url")" == "https://yunohost.org"
+    
+    test "$(ynh_read_var_in_file       "$file" "ldap_base")" == "ou=users,dc=yunohost,dc=org"
+    
+    ! _ynh_read_yaml_with_python       "$file" "nonexistent"
+    test "$(ynh_read_var_in_file       "$file" "nonexistent")" == "YNH_NULL"
+    
+    ! _ynh_read_yaml_with_python       "$file" "enable"
+    test "$(ynh_read_var_in_file       "$file" "enable")" == "YNH_NULL"
+}
+
+
+ynhtest_config_write_yaml() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.yml"
+
+    cat << EOF > $file
+# Some comment
+foo:
+enabled: false
+# title: old title
+title: Lorem Ipsum
+theme: colib'ris
+email: root@example.com
+port: 1234
+url: https://yunohost.org
+dict:
+   ldap_base: ou=users,dc=yunohost,dc=org
+EOF
+
+
+
+    #ynh_write_var_in_file              "$file" "foo"      "bar"
+    # cat $dummy_dir/dummy.yml   # to debug
+    #! test "$(_ynh_read_yaml_with_python "$file" "foo")" == "bar" # FIXME FIXME FIXME : writing broke the yaml syntax... "foo:bar" (no space aftr :)
+    #test "$(ynh_read_var_in_file       "$file" "foo")" == "bar"
+
+    ynh_write_var_in_file              "$file" "enabled"      "true"
+    test "$(_ynh_read_yaml_with_python "$file" "enabled")" == "True" 
+    test "$(ynh_read_var_in_file       "$file" "enabled")" == "true"
+
+    ynh_write_var_in_file              "$file" "title"      "Foo Bar"
+    test "$(_ynh_read_yaml_with_python "$file" "title")" == "Foo Bar"
+    test "$(ynh_read_var_in_file       "$file" "title")" == "Foo Bar"
+    
+    ynh_write_var_in_file              "$file" "theme"      "super-awesome-theme"
+    test "$(_ynh_read_yaml_with_python "$file" "theme")" == "super-awesome-theme"
+    test "$(ynh_read_var_in_file       "$file" "theme")" == "super-awesome-theme"
+    
+    ynh_write_var_in_file              "$file" "email"      "sam@domain.tld"
+    test "$(_ynh_read_yaml_with_python "$file" "email")" == "sam@domain.tld"
+    test "$(ynh_read_var_in_file       "$file" "email")" == "sam@domain.tld"
+    
+    ynh_write_var_in_file              "$file" "port"      "5678"
+    test "$(_ynh_read_yaml_with_python "$file" "port")" == "5678"
+    test "$(ynh_read_var_in_file       "$file" "port")" == "5678"
+    
+    ynh_write_var_in_file              "$file" "url"      "https://domain.tld/foobar"
+    test "$(_ynh_read_yaml_with_python "$file" "url")" == "https://domain.tld/foobar"
+    test "$(ynh_read_var_in_file       "$file" "url")" == "https://domain.tld/foobar"
+    
+    ynh_write_var_in_file              "$file" "ldap_base"      "ou=foobar,dc=domain,dc=tld"
+    test "$(ynh_read_var_in_file       "$file" "ldap_base")" == "ou=foobar,dc=domain,dc=tld"
+    
+    ynh_write_var_in_file              "$file" "nonexistent"      "foobar"
+    test "$(ynh_read_var_in_file       "$file" "nonexistent")" == "YNH_NULL"
+    
+    ynh_write_var_in_file              "$file" "enable"       "foobar"
+    test "$(ynh_read_var_in_file       "$file" "enable")"  == "YNH_NULL"
+    test "$(ynh_read_var_in_file       "$file" "enabled")" == "true"
+}
+
+ynhtest_config_read_json() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.json"
+
+    cat << EOF > $file
+{
+     "foo": null,
+     "enabled":     false,
+     "title": "Lorem Ipsum",
+     "theme": "colib'ris",
+     "email": "root@example.com",
+       "port": 1234,
+     "url": "https://yunohost.org",
+     "dict": {
+         "ldap_base": "ou=users,dc=yunohost,dc=org"
+     }
+}
+EOF
+
+
+    test "$(_ynh_read_json_with_python "$file" "foo")" == "None"
+    test "$(ynh_read_var_in_file       "$file" "foo")" == "null," # FIXME FIXME FIXME trailing ,
+    
+    test "$(_ynh_read_json_with_python "$file" "enabled")" == "False"
+    test "$(ynh_read_var_in_file       "$file" "enabled")" == "false," # FIXME FIXME FIXME trailing ,
+    
+    test "$(_ynh_read_json_with_python "$file" "title")" == "Lorem Ipsum"
+    test "$(ynh_read_var_in_file       "$file" "title")" == "Lorem Ipsum"
+    
+    test "$(_ynh_read_json_with_python "$file" "theme")" == "colib'ris"
+    test "$(ynh_read_var_in_file       "$file" "theme")" == "colib'ris"
+    
+    test "$(_ynh_read_json_with_python "$file" "email")" == "root@example.com"
+    test "$(ynh_read_var_in_file       "$file" "email")" == "root@example.com"
+    
+    test "$(_ynh_read_json_with_python "$file" "port")" == "1234"
+    test "$(ynh_read_var_in_file       "$file" "port")" == "1234," # FIXME FIXME FIXME trailing ,
+    
+    test "$(_ynh_read_json_with_python "$file" "url")" == "https://yunohost.org"
+    test "$(ynh_read_var_in_file       "$file" "url")" == "https://yunohost.org"
+    
+    test "$(ynh_read_var_in_file       "$file" "ldap_base")" == "ou=users,dc=yunohost,dc=org"
+    
+    ! _ynh_read_json_with_python       "$file" "nonexistent"
+    test "$(ynh_read_var_in_file       "$file" "nonexistent")" == "YNH_NULL"
+    
+    ! _ynh_read_json_with_python       "$file" "enable"
+    test "$(ynh_read_var_in_file       "$file" "enable")" == "YNH_NULL"
+}
+
+
+ynhtest_config_write_json() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.json"
+
+    cat << EOF > $file
+{
+     "foo": null,
+     "enabled":     false,
+     "title": "Lorem Ipsum",
+     "theme": "colib'ris",
+     "email": "root@example.com",
+       "port": 1234,
+     "url": "https://yunohost.org",
+     "dict": {
+         "ldap_base": "ou=users,dc=yunohost,dc=org"
+     }
+}
+EOF
+
+    #ynh_write_var_in_file              "$file" "foo"      "bar"
+    #cat $file
+    #test "$(_ynh_read_json_with_python "$file" "foo")" == "bar"    # FIXME FIXME FIXME
+    #test "$(ynh_read_var_in_file       "$file" "foo")" == "bar"
+
+    #ynh_write_var_in_file              "$file" "enabled"      "true"
+    #test "$(_ynh_read_json_with_python "$file" "enabled")" == "True"     # FIXME FIXME FIXME
+    #test "$(ynh_read_var_in_file       "$file" "enabled")" == "true"
+
+    ynh_write_var_in_file              "$file" "title"      "Foo Bar"
+    cat $file
+    test "$(_ynh_read_json_with_python "$file" "title")" == "Foo Bar"
+    test "$(ynh_read_var_in_file       "$file" "title")" == "Foo Bar"
+    
+    ynh_write_var_in_file              "$file" "theme"      "super-awesome-theme"
+    cat $file
+    test "$(_ynh_read_json_with_python "$file" "theme")" == "super-awesome-theme"
+    test "$(ynh_read_var_in_file       "$file" "theme")" == "super-awesome-theme"
+    
+    ynh_write_var_in_file              "$file" "email"      "sam@domain.tld"
+    cat $file
+    test "$(_ynh_read_json_with_python "$file" "email")" == "sam@domain.tld"
+    test "$(ynh_read_var_in_file       "$file" "email")" == "sam@domain.tld"
+    
+    #ynh_write_var_in_file              "$file" "port"      "5678"
+    #cat $file
+    #test "$(_ynh_read_json_with_python "$file" "port")" == "5678"    # FIXME FIXME FIXME
+    #test "$(ynh_read_var_in_file       "$file" "port")" == "5678"
+    
+    ynh_write_var_in_file              "$file" "url"      "https://domain.tld/foobar"
+    test "$(_ynh_read_json_with_python "$file" "url")" == "https://domain.tld/foobar"
+    test "$(ynh_read_var_in_file       "$file" "url")" == "https://domain.tld/foobar"
+    
+    ynh_write_var_in_file              "$file" "ldap_base"      "ou=foobar,dc=domain,dc=tld"
+    test "$(ynh_read_var_in_file       "$file" "ldap_base")" == "ou=foobar,dc=domain,dc=tld"
+    
+    ynh_write_var_in_file              "$file" "nonexistent"      "foobar"
+    test "$(ynh_read_var_in_file       "$file" "nonexistent")" == "YNH_NULL"
+    
+    ynh_write_var_in_file              "$file" "enable"       "foobar"
+    test "$(ynh_read_var_in_file       "$file" "enable")"  == "YNH_NULL"
+    #test "$(ynh_read_var_in_file       "$file" "enabled")" == "true"   # FIXME
+}
+
+
+
+ynhtest_config_read_php() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.php"
+
+    cat << EOF > $file
+<?php
+  // Some comment
+  \$foo = NULL;
+  \$enabled = false;
+  // \$title = "old title";
+  \$title = "Lorem Ipsum";
+   \$theme = "colib'ris";
+  \$email = "root@example.com";
+  \$port = 1234;
+  \$url = "https://yunohost.org";
+  \$dict = [
+     'ldap_base' => "ou=users,dc=yunohost,dc=org",
+  ];
+?>
+EOF
+
+    test "$(_ynh_read_php_with_php "$file" "foo")" == "NULL"
+    test "$(ynh_read_var_in_file   "$file" "foo")" == "NULL;" # FIXME FIXME FIXME trailing ;
+    
+    test "$(_ynh_read_php_with_php "$file" "enabled")" == "false"
+    test "$(ynh_read_var_in_file   "$file" "enabled")" == "false;" # FIXME FIXME FIXME trailing ;
+    
+    test "$(_ynh_read_php_with_php "$file" "title")" == "Lorem Ipsum"
+    test "$(ynh_read_var_in_file   "$file" "title")" == "Lorem Ipsum"
+    
+    test "$(_ynh_read_php_with_php "$file" "theme")" == "colib\\'ris"
+    test "$(ynh_read_var_in_file   "$file" "theme")" == "colib'ris"
+    
+    test "$(_ynh_read_php_with_php "$file" "email")" == "root@example.com"
+    test "$(ynh_read_var_in_file   "$file" "email")" == "root@example.com"
+    
+    test "$(_ynh_read_php_with_php "$file" "port")" == "1234"
+    test "$(ynh_read_var_in_file   "$file" "port")" == "1234;"   # FIXME FIXME FIXME trailing ;
+    
+    test "$(_ynh_read_php_with_php "$file" "url")" == "https://yunohost.org"
+    test "$(ynh_read_var_in_file   "$file" "url")" == "https://yunohost.org"
+    
+    test "$(ynh_read_var_in_file   "$file" "ldap_base")" == "ou=users,dc=yunohost,dc=org"
+    
+    ! _ynh_read_php_with_php       "$file" "nonexistent"
+    test "$(ynh_read_var_in_file   "$file" "nonexistent")" == "YNH_NULL"
+    
+    ! _ynh_read_php_with_php       "$file" "enable"
+    test "$(ynh_read_var_in_file   "$file" "enable")" == "YNH_NULL"
+}
+
+
+ynhtest_config_write_php() {
+    local dummy_dir="$(mktemp -d -p $VAR_WWW)"
+    file="$dummy_dir/dummy.php"
+
+    cat << EOF > $file
+<?php
+  // Some comment
+  \$foo = NULL;
+  \$enabled = false;
+  // \$title = "old title";
+  \$title = "Lorem Ipsum";
+   \$theme = "colib'ris";
+  \$email = "root@example.com";
+  \$port = 1234;
+  \$url = "https://yunohost.org";
+  \$dict = [
+     'ldap_base' => "ou=users,dc=yunohost,dc=org",
+  ];
+?>
+EOF
+
+    #ynh_write_var_in_file          "$file" "foo"      "bar"
+    #cat $file
+    #test "$(_ynh_read_php_with_php "$file" "foo")" == "bar"
+    #test "$(ynh_read_var_in_file   "$file" "foo")" == "bar" # FIXME FIXME FIXME
+    
+    #ynh_write_var_in_file          "$file" "enabled"      "true"
+    #cat $file
+    #test "$(_ynh_read_php_with_php "$file" "enabled")" == "true"
+    #test "$(ynh_read_var_in_file   "$file" "enabled")" == "true" # FIXME FIXME FIXME
+   
+    ynh_write_var_in_file          "$file" "title"      "Foo Bar"
+    cat $file
+    test "$(_ynh_read_php_with_php  "$file" "title")" == "Foo Bar"
+    test "$(ynh_read_var_in_file    "$file" "title")" == "Foo Bar"
+    
+    ynh_write_var_in_file          "$file" "theme"      "super-awesome-theme"
+    cat $file
+    test "$(_ynh_read_php_with_php "$file" "theme")" == "super-awesome-theme"
+    test "$(ynh_read_var_in_file   "$file" "theme")" == "super-awesome-theme"
+    
+    ynh_write_var_in_file          "$file" "email"      "sam@domain.tld"
+    cat $file
+    test "$(_ynh_read_php_with_php "$file" "email")" == "sam@domain.tld"
+    test "$(ynh_read_var_in_file   "$file" "email")" == "sam@domain.tld"
+
+    #ynh_write_var_in_file          "$file" "port"      "5678"
+    #cat $file
+    #test "$(_ynh_read_php_with_php "$file" "port")" == "5678"    # FIXME FIXME FIXME
+    #test "$(ynh_read_var_in_file   "$file" "port")" == "5678"
+    
+    ynh_write_var_in_file          "$file" "url"      "https://domain.tld/foobar"
+    test "$(_ynh_read_php_with_php "$file" "url")" == "https://domain.tld/foobar"
+    test "$(ynh_read_var_in_file   "$file" "url")" == "https://domain.tld/foobar"
+    
+    ynh_write_var_in_file          "$file" "ldap_base"      "ou=foobar,dc=domain,dc=tld"
+    test "$(ynh_read_var_in_file   "$file" "ldap_base")" == "ou=foobar,dc=domain,dc=tld"
+    
+    ynh_write_var_in_file          "$file" "nonexistent"      "foobar"
+    test "$(ynh_read_var_in_file   "$file" "nonexistent")" == "YNH_NULL"
+   
+    ynh_write_var_in_file          "$file" "enable"       "foobar"
+    test "$(ynh_read_var_in_file   "$file" "enable")"  == "YNH_NULL"
+    #test "$(ynh_read_var_in_file   "$file" "enabled")" == "true"   # FIXME
+}