1 files changed, 97 insertions, 0 deletions
diff --git a/alv-lib/testing.moon b/alv-lib/testing.moon
new file mode 100644
index 0000000..a321e43
--- /dev/null
+++ b/alv-lib/testing.moon
@@ -0,0 +1,97 @@
+import Constant, Op, Builtin, Input, Error, T, any, const from require "alv.base"
+import Tag, Cell from require "alv"
+
+assert_ = Constant.meta
+  meta:
+    name: 'assert'
+    summary: "Throw an error if a condition is false."
+    examples: { "(assert check [msg])" }
+    description: "
+Check is any bool result. When it is `false`, this op throws an error.
+`msg` is a str= value that is used as the error message.
+By default, the message contains the failing check expression."
+
+  value: class extends Builtin
+    assertOp = class extends Op
+      pattern = any.bool + const.str
+      setup: (inputs) =>
+        { check, msg } = pattern\match inputs
+
+        super
+          check: Input.hot check
+          msg: msg and Input.cold msg
+
+      tick: =>
+        { :check, :msg } = @unwrap_all!
+
+        if not check
+          error Error 'assertion', msg or "assertion failed"
+
+    eval: (scope, tail) =>
+      L\trace "evaling #{@}"
+      assert #tail == 1 or #tail == 2, "'assert' takes one or two arguments"
+
+      tag = @tag\clone Tag.parse '-1'
+      inner = Cell tag, {
+        Constant.literal T.opdef, assertOp, 'assert'
+        tail[1]
+        tail[2] or Constant.str "assertion failed: #{tail[1]\stringify 2}"
+      }
+      super inner\eval scope
+
+expect_eq = Constant.meta
+  meta:
+    name: 'expect='
+    summary: "Throw an error if arguments aren't equal."
+    examples: { "(expect= expected actual [actual…])" }
+    description: "
+Check if `expected` and `actual` are equal.
+If not, throws an error."
+
+  value: class extends Builtin
+    expectOp = class extends Op
+      pattern = any! + (any! + const.str)\named('val', 'src')*0
+      setup: (inputs) =>
+        { expected, values } = pattern\match inputs
+
+        super
+          expected: Input.hot expected
+          values: [Input.hot got.val for got in *values]
+          sources: [Input.cold got.src for got in *values]
+
+        type = expected\type!
+        for i, val in ipairs @inputs.values
+          same = type == val\type!
+          assert same, Error 'assertion', "Expected #{@inputs.sources[i]!} to equal #{expected.result} (got #{val.result})"
+
+      tick: =>
+        type = @inputs.expected\type!
+        expected = @inputs.expected!
+
+        for i, val in ipairs @inputs.values
+          assert (type\eq expected, val!), Error 'assertion', "Expected #{@inputs.sources[i]!} to equal #{@inputs.expected.result} (got #{val.result})"
+
+    eval: (scope, tail) =>
+      L\trace "evaling #{@}"
+      assert #tail > 1, "'expect=' takes at least two arguments"
+
+      children = {
+        Constant.literal T.opdef, expectOp, 'assert'
+        tail[1]
+      }
+      for arg in *tail[2,]
+        table.insert children, arg
+        table.insert children, Constant.str arg\stringify 2
+
+      tag = @tag\clone Tag.parse '-1'
+      inner = Cell tag, children
+      super inner\eval scope
+
+Constant.meta
+  meta:
+    name: 'testing'
+    summary: "Operators for testing."
+
+  value:
+    'assert': assert_
+    'expect=': expect_eq