Merge d20a732 into b216be6

README.md

@@ -134,8 +134,7 @@ There's also type checks for arrays and interfaces but we'll cover those in thei
 
 t includes a few special functions for checking numbers, these can be useful to ensure the given value is within a certain range.
 
-**General:**
-
+**General:**\
 **`t.nan`**\
 determines if value is `NaN`\
 All of the following checks will not pass for `NaN` values.\
@@ -170,6 +169,13 @@ checks `t.number` and determines if value < max
 **`t.numberConstrainedExclusive(min, max)`**\
 checks `t.number` and determines if min < value < max
 
+## Special String Functions
+
+t includes a few special functions for checking strings
+
+**`t.match(pattern)`**\
+checks `t.string` and determines if value matches the pattern via `string.match(value, pattern)`
+
 ## Arrays
 In Lua, arrays are a special type of table where all the keys are sequential integers.\
 t has special functions for checking against arrays.

lib/init.lua

@@ -571,6 +571,29 @@ function t.numberConstrainedExclusive(min, max)
 	end
 end
 
+--[[**
+	ensures value matches string pattern
+
+	@param string pattern to check against
+
+	@returns A function that will return true iff the condition is passed
+**--]]
+function t.match(pattern)
+	assert(t.string(pattern))
+	return function(value)
+		local stringSuccess, stringErrMsg = t.string(value)
+		if not stringSuccess then
+			return false, stringErrMsg
+		end
+
+		if string.match(value, pattern) == nil then
+			return false, string.format("\"%s\" failed to match pattern \"%s\"", value, pattern)
+		end
+
+		return true
+	end
+end
+
 --[[**
 	ensures value is either nil or passes check
 

lib/init.spec.lua

@@ -501,4 +501,10 @@ return function()
 			assert(not (myInterface({ buttonInFrame = frame })))
 		end
 	end)
+
+	it("should support t.match", function()
+		local check = t.match("%d+")
+		assert(check("123"))
+		assert(not (check("abc")))
+	end)
 end

lib/t.d.ts

@@ -102,6 +102,8 @@ interface t {
 	numberConstrained: (min: number, max: number) => (value: unknown) => value is number;
 	/** checks to see if `value` is a number and `min < value < max` */
 	numberConstrainedExclusive: (min: number, max: number) => (value: unknown) => value is number;
+	/** checks `t.string` and determines if value matches the pattern via `string.match(value, pattern)` */
+	match: (pattern: string) => check<string>;
 	/** checks to see if `value` is either nil or passes `check` */
 	optional: <T>(check: (value: unknown) => value is T) => check<T | undefined>;
 	/** checks to see if `value` is a table and if its keys match against `check */