test if and when builtins

1 files changed, 92 insertions, 0 deletions

diff --git a/spec/lang/cond_spec.moon b/spec/lang/cond_spec.moon
new file mode 100644
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+++ b/spec/lang/cond_spec.moon
@@ -0,0 +1,92 @@
+import TestPilot from require 'spec.test_setup'
+import T, Struct, Array, Constant from require 'alv'
+
+describe "if", ->
+  COPILOT = TestPilot!
+
+  it "checks truthiness", ->
+    for truthy in *{'true', '1', '-1', '1234', '(array 1 2 3)', '"test"', '""'}
+      with COPILOT\eval_once "(if #{truthy} 'yes' 'no')"
+        assert.is.true \is_const!
+        assert.is.equal 'yes', .result!
+
+    for falsy in *{'false', '0'}
+      with COPILOT\eval_once "(if #{falsy} 'yes' 'no')"
+        assert.is.true \is_const!
+        assert.is.equal 'no', .result!
+
+  it "can be used without else clause", ->
+    with COPILOT\eval_once '(if true "yes")'
+      assert.is.true \is_const!
+      assert.is.equal 'yes', .result!
+
+    with COPILOT\eval_once '(if false "yes")'
+      assert.is.true \is_const!
+      assert.is.equal nil, .result
+
+  it "doesn't evaluate the untaken branch", ->
+    with COPILOT\eval_once '(if true "yes" (error/doesnt-exist))'
+      assert.is.true \is_const!
+      assert.is.equal 'yes', .result!
+
+    with COPILOT\eval_once '(if false (error/doesnt-exist) "no")'
+      assert.is.true \is_const!
+      assert.is.equal 'no', .result!
+
+  it "errors on non-const choice", ->
+    err = assert.has.error ->
+      COPILOT\eval_once '(import* time) (if (ramp 1) "yes" "no")'
+    assert.matches "'if'%-expression needs to be constant", err
+
+  it "forwards any result", ->
+    with COPILOT\eval_once '
+        (import* time)
+        (if true (every 1 (array 1 2 3)))'
+      assert.is.false \is_const!
+      assert.is.equal '<num[3]! nil>', tostring .result
+
+describe "when", ->
+  COPILOT = TestPilot!
+
+  it "checks truthiness", ->
+    for truthy in *{'true', '1', '-1', '1234', '(array 1 2 3)', '"test"', '""'}
+      with COPILOT\eval_once "(when #{truthy} 'yes')"
+        assert.is.true \is_const!
+        assert.is.equal 'yes', .result!
+
+    for falsy in *{'false', '0'}
+      with COPILOT\eval_once "(when #{falsy} 'yes')"
+        assert.is.true \is_const!
+        assert.is.nil .result
+
+  it "doesn't evaluate if falsy", ->
+    with COPILOT\eval_once '(when false (error/doesnt-exist))'
+      assert.is.true \is_const!
+      assert.is.nil, .result
+
+    with COPILOT\eval_once '
+        (when false
+          (error/doesnt-exist)
+          (error/doesnt-exist)
+          (error/doesnt-exist))'
+      assert.is.true \is_const!
+      assert.is.nil, .result
+
+  it "errors on non-const choice", ->
+    err = assert.has.error ->
+      COPILOT\eval_once '(import* time) (when (ramp 1) 1 2 3)'
+    assert.matches "'when'%-expression needs to be constant", err
+
+  it "forwards any result", ->
+    with COPILOT\eval_once '
+        (import* time)
+        (when true
+          (every 1 (array 1 2 3))
+          1 2 3)'
+      assert.is.false \is_const!
+      assert.is.equal '<num~ 3>', tostring .result
+
+    with COPILOT\eval_once '(when true (array 1 2 3))'
+      assert.is.true \is_const!
+      assert.is.equal '<num[3]= [1 2 3]>', tostring .result
+