feat(router): lua validate an expression against a schema

Makefile

@@ -23,9 +23,11 @@ build: target/release/libatc_router.$(SHLIB_EXT) target/release/libatc_router.a
 target/release/libatc_router.%: src/*.rs
 	cargo build --release
 
-install: build
+install-lualib:
 	$(INSTALL) -d $(DESTDIR)$(LUA_LIB_DIR)/resty/router/
 	$(INSTALL) -m 664 lib/resty/router/*.lua $(DESTDIR)$(LUA_LIB_DIR)/resty/router/
+
+install: build install-lualib
 	$(INSTALL) -m 775 target/release/libatc_router.$(SHLIB_EXT) $(DESTDIR)$(LUA_LIB_DIR)/libatc_router.$(SHLIB_EXT)
 
 clean:

README.md

@@ -18,6 +18,7 @@ Table of Contents
         * [remove\_matcher](#remove_matcher)
         * [execute](#execute)
         * [get\_fields](#get_fields)
+        * [validate](#validate)
     * [resty.router.context](#restyroutercontext)
         * [new](#new)
         * [add\_value](#add_value)
@@ -144,6 +145,21 @@ actually used by the user supplied matchers.
 
 [Back to TOC](#table-of-contents)
 
+### validate
+
+**syntax:** *ok, err = router.validate(schema, expr)*
+
+**context:** *any*
+
+Validates an expression against a given schema.
+
+Returns `true` when the expression is valid.
+
+If the expression is invalid,
+`nil` and a string describing the reason will be returned.
+
+[Back to TOC](#table-of-contents)
+
 ## resty.router.context
 
 ### new

lib/resty/router/router.lua

@@ -98,4 +98,33 @@ function _M:get_fields()
 end
 
 
+do
+    local ROUTERS = setmetatable({}, { __mode = "k" })
+    local DEFAULT_UUID = "00000000-0000-0000-0000-000000000000"
+    local DEFAULT_PRIORITY = 0
+
+    -- validate an expression against a schema
+    -- @param expr the expression to validate
+    -- @param schema the schema to validate against
+    -- @return true if the expression is valid, (nil, error) otherwise
+    function _M.validate(schema, expr)
+        local r = ROUTERS[schema]
+
+        if not r then
+            r = _M.new(schema, 1)
+            ROUTERS[schema] = r
+        end
+
+        local ok, err = r:add_matcher(DEFAULT_PRIORITY, DEFAULT_UUID, expr)
+        if not ok then
+            return nil, err
+        end
+
+        assert(r:remove_matcher(DEFAULT_UUID))
+
+        return true
+    end
+end
+
+
 return _M

t/06-validate.t

@@ -0,0 +1,242 @@
+# vim:set ft= ts=4 sw=4 et:
+
+use Test::Nginx::Socket::Lua;
+use Cwd qw(cwd);
+
+repeat_each(2);
+
+plan tests => repeat_each() * blocks() * 5;
+
+my $pwd = cwd();
+
+our $HttpConfig = qq{
+    lua_package_path "$pwd/lib/?.lua;;";
+    lua_package_cpath "$pwd/target/debug/?.so;;";
+};
+
+no_long_string();
+no_diff();
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: test valid schema + expr
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = "http.headers.foo == \"bar\""
+            local r, err = router.validate(s, expr)
+
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+nil
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 2: test type inconsistency (schema is String, expr is Int)
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = "http.headers.foo == 123"
+            local r, err = router.validate(s, expr)
+
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body_like
+nil
+Type mismatch between the LHS and RHS values of predicate
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 3: test invalid schema + invalid expr
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = "== 123"
+            local r, err = router.validate(s, expr)
+
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+nil
+ --> 1:1
+  |
+1 | == 123
+  | ^---
+  |
+  = expected term
+
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 4: test valid schema + invalid expr
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = "== \"bar\""
+            local r, err = router.validate(s, expr)
+
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+nil
+ --> 1:1
+  |
+1 | == "bar"
+  | ^---
+  |
+  = expected term
+
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 5: valid regex
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = [[http.headers.foo ~ "/\\\\/*user$"]]
+            local r, err = router.validate(s, expr)
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+nil
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 6: invalid regex
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = [[http.headers.foo ~ "([."]]
+            local r, err = router.validate(s, expr)
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+nil
+ --> 1:1
+  |
+1 | http.headers.foo ~ "([."
+  | ^----------------------^
+  |
+  = regex parse error:
+    ([.
+     ^
+error: unclosed character class
+
+--- no_error_log
+[error]
+[warn]
+[crit]
+
+
+=== TEST 7: Rust regex 1.8.x will not think the regex is invalid
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            local schema = require("resty.router.schema")
+            local router = require("resty.router.router")
+
+            local s = schema.new()
+            s:add_field("http.headers.foo", "String")
+
+            local expr = [[http.headers.foo ~ "/\\/*user$"]]
+            local r, err = router.validate(s, expr)
+            ngx.say(r)
+            ngx.say(err)
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+nil
+--- no_error_log
+[error]
+[warn]
+[crit]