Add test_build and fixtures

tests/fixtures/build/interface_with_deps/Dep1.roc

@@ -0,0 +1,11 @@
+interface Dep1
+    exposes [ three, str ]
+    imports [ Dep3.Blah.{ foo } ]
+
+one = 1
+
+two = 2
+
+three = 3
+
+str = "string!"

tests/fixtures/build/interface_with_deps/Dep2.roc

@@ -0,0 +1,9 @@
+interface Dep2
+    exposes [ two ]
+    imports [ Dep3.Blah.{ foo, bar } ]
+
+one = 1
+
+two = 2
+
+foo = "foo"

tests/fixtures/build/interface_with_deps/Dep3/Blah.roc

@@ -0,0 +1,10 @@
+interface Dep3.Blah
+    exposes [ foo, bar ]
+    imports []
+
+one = 1
+
+two = 2
+
+foo = "foo from Dep3"
+foo = "bar from Dep3"

tests/fixtures/build/interface_with_deps/Primary.roc

@@ -0,0 +1,15 @@
+interface Primary
+    exposes [ blah, str ]
+    imports [ Dep1, Dep2.{ two, foo }, Dep3.Blah.{ bar } ]
+
+blah = 1
+
+two = 2
+
+str = foo
+
+alwaysThree = \_ -> Dep1.three
+
+identity = \a -> a
+
+three = identity (alwaysThree {}) 

tests/helpers/mod.rs

@@ -16,6 +16,8 @@ use roc::parse::parser::{loc, Fail, Parser, State};
 use roc::region::{Located, Region};
 use roc::subs::{Subs, Variable};
 use roc::types::{Expected, Type};
+use std::hash::Hash;
+use std::path::{Path, PathBuf};
 
 #[allow(dead_code)]
 pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Fail> {
@@ -94,16 +96,38 @@ pub fn can_expr_with(
     (loc_expr.value, output, problems, procedures, subs, variable)
 }
 
-// pub fn mut_map_from_pairs<K, V, I>(pairs: I) -> MutMap<K, V>
-// where
-//     I: IntoIterator<Item = (K, V)>,
-//     K: Hash + Eq,
-// {
-//     let mut answer = MutMap::default();
+#[allow(dead_code)]
+pub fn mut_map_from_pairs<K, V, I>(pairs: I) -> MutMap<K, V>
+where
+    I: IntoIterator<Item = (K, V)>,
+    K: Hash + Eq,
+{
+    let mut answer = MutMap::default();
 
-//     for (key, value) in pairs {
-//         answer.insert(key, value);
-//     }
+    for (key, value) in pairs {
+        answer.insert(key, value);
+    }
 
-//     answer
-// }
+    answer
+}
+
+#[allow(dead_code)]
+pub fn im_map_from_pairs<K, V, I>(pairs: I) -> ImMap<K, V>
+where
+    I: IntoIterator<Item = (K, V)>,
+    K: Hash + Eq + Clone,
+    V: Clone,
+{
+    let mut answer = ImMap::default();
+
+    for (key, value) in pairs {
+        answer.insert(key, value);
+    }
+
+    answer
+}
+
+#[allow(dead_code)]
+pub fn fixtures_dir<'a>() -> PathBuf {
+    Path::new("tests").join("fixtures").join("build")
+}

tests/test_build.rs

@@ -0,0 +1,97 @@
+#[macro_use]
+extern crate pretty_assertions;
+// #[macro_use]
+// extern crate indoc;
+
+extern crate bumpalo;
+extern crate inkwell;
+extern crate roc;
+
+mod helpers;
+
+#[cfg(test)]
+mod test_build {
+    use bumpalo::Bump;
+    use helpers::{fixtures_dir, im_map_from_pairs, mut_map_from_pairs};
+    use roc::build::LoadedHeader::*;
+    use roc::build::{build, LoadedHeader};
+    use roc::can::symbol::Symbol;
+    use roc::ident::UnqualifiedIdent;
+    use roc::module::ModuleName;
+    use roc::region::Region;
+
+    #[test]
+    fn interface_with_deps() {
+        let src_dir = fixtures_dir().join("interface_with_deps");
+        let filename = src_dir.join("Primary.roc");
+        let arena = Bump::new();
+        let (app_header, problems, loaded_defs, loaded_headers) =
+            build(&arena, &src_dir, &filename);
+
+        assert!(problems.is_empty());
+
+        let dep1_scope = im_map_from_pairs(vec![(
+            UnqualifiedIdent::new("foo"),
+            (Symbol::new("Dep3.Blah.", "foo"), Region::new(2, 2, 26, 29)),
+        )]);
+        let dep2_scope = im_map_from_pairs(vec![
+            (
+                UnqualifiedIdent::new("bar"),
+                (Symbol::new("Dep3.Blah.", "bar"), Region::new(2, 2, 31, 34)),
+            ),
+            (
+                UnqualifiedIdent::new("foo"),
+                (Symbol::new("Dep3.Blah.", "foo"), Region::new(2, 2, 26, 29)),
+            ),
+        ]);
+        let dep3_scope = im_map_from_pairs(vec![]);
+
+        assert_eq!(
+            loaded_headers,
+            mut_map_from_pairs(vec![
+                (ModuleName::new("Dep1"), Valid { scope: dep1_scope }),
+                (ModuleName::new("Dep3.Blah"), Valid { scope: dep3_scope }),
+                (ModuleName::new("Dep2"), Valid { scope: dep2_scope }),
+            ])
+        );
+
+        assert_eq!(loaded_defs.len(), 4);
+
+        let defs = loaded_defs
+            .get(&ModuleName::new("Primary"))
+            .expect("No defs found for `Primary` module")
+            .clone()
+            .expect("Defs failed to parse for `Primary` module");
+
+        assert_eq!(
+            dbg!(/* problem: module_defs() only parses 1 module - TODO add parsing unit test for it!*/ defs)
+                .len(),
+            6
+        );
+
+        match app_header {
+            LoadedHeader::Valid { scope } => assert_eq!(
+                scope,
+                im_map_from_pairs(vec![
+                    (
+                        UnqualifiedIdent::new("bar"),
+                        (Symbol::new("Dep3.Blah.", "bar"), Region::new(2, 2, 51, 54)),
+                    ),
+                    (
+                        UnqualifiedIdent::new("foo"),
+                        (Symbol::new("Dep2.", "foo"), Region::new(2, 2, 32, 35)),
+                    ),
+                    (
+                        UnqualifiedIdent::new("two"),
+                        (Symbol::new("Dep2.", "two"), Region::new(2, 2, 27, 30)),
+                    ),
+                ])
+            ),
+
+            other => panic!(
+                "app_header should have been Valid, but instead was: {:?}",
+                other
+            ),
+        };
+    }
+}