chore: add acceptance tests for if/is

examples/acceptance_tests/105/aiken.lock

@@ -0,0 +1,7 @@
+# This file was generated by Aiken
+# You typically do not need to edit this file
+
+requirements = []
+packages = []
+
+[etags]

examples/acceptance_tests/105/aiken.toml

@@ -0,0 +1,9 @@
+name = "aiken-lang/105"
+version = "0.0.0"
+license = "Apache-2.0"
+description = "Aiken contracts for project 'aiken-lang/102'"
+
+[repository]
+user = "aiken-lang"
+project = "105"
+platform = "github"

examples/acceptance_tests/105/lib/tests.ak

@@ -0,0 +1,45 @@
+pub type Foo {
+  a: Int,
+}
+
+pub type Bar {
+  Bazz(Int)
+  Buzz(Int)
+}
+
+test if_soft_cast() {
+  let d: Data = Foo { a: 1 }
+
+  if d is Foo {
+    d.a == 1
+  } else {
+    False
+  }
+}
+
+test if_soft_cast_2() {
+  let d: Data = Bazz(1)
+
+  if d is Foo {
+    d.a == 1
+  } else if d is Bazz(y): Bar {
+    y == 1
+  } else {
+    False
+  }
+}
+
+test if_soft_cast_3() {
+  let d: Data = Bazz(1)
+  let x: Data = Buzz(2)
+
+  if d is Foo {
+    d.a == 1
+  } else if d is Bazz(y): Bar {
+    y == 1
+  } else if x is Buzz(y): Bar {
+    y == 2
+  } else {
+    False
+  }
+}