refactor: remove old test harness

4 files changed, 16 insertions, 710 deletions

diff --git a/dhall/build.rs b/dhall/build.rs
index 660d76a..4fc8545 100644
--- a/dhall/build.rs
+++ b/dhall/build.rs
@@ -1,351 +1,10 @@
 use std::env;
-use std::ffi::OsString;
 use std::fs::{read_to_string, File};
 use std::io::{BufRead, BufReader, Write};
-use std::path::{Path, PathBuf};
-use std::rc::Rc;
-use walkdir::WalkDir;
+use std::path::Path;
 
 use abnf_to_pest::render_rules_to_pest;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-enum FileType {
-    /// Dhall source file
-    Text,
-    /// Dhall binary file
-    Binary,
-    /// Text file with hash
-    Hash,
-    /// Text file with expected text output
-    UI,
-}
-
-impl FileType {
-    fn to_ext(self) -> &'static str {
-        match self {
-            FileType::Text => "dhall",
-            FileType::Binary => "dhallb",
-            FileType::Hash => "hash",
-            FileType::UI => "txt",
-        }
-    }
-    fn constructor(self) -> &'static str {
-        match self {
-            FileType::Text => "TestFile::Source",
-            FileType::Binary => "TestFile::Binary",
-            FileType::Hash => "TestFile::Binary",
-            FileType::UI => "TestFile::UI",
-        }
-    }
-    fn construct(self, path: &str) -> String {
-        // e.g. with
-        //  path = "tests/foor/barA"
-        // returns something like:
-        //  TestFile::Source("tests/foor/barA.dhall")
-        format!(r#"{}("{}.{}")"#, self.constructor(), path, self.to_ext())
-    }
-}
-
-fn dhall_files_in_dir<'a>(
-    dir: &'a Path,
-    take_ab_suffix: bool,
-    filetype: FileType,
-) -> impl Iterator<Item = (String, String)> + 'a {
-    WalkDir::new(dir)
-        .into_iter()
-        .filter_map(|e| e.ok())
-        .filter_map(move |path| {
-            let path = path.path().strip_prefix(dir).unwrap();
-            let ext = path.extension()?;
-            if *ext != OsString::from(filetype.to_ext()) {
-                return None;
-            }
-            let path = path.to_string_lossy();
-            let path = &path[..path.len() - 1 - ext.len()];
-            let path = if take_ab_suffix && &path[path.len() - 1..] != "A" {
-                return None;
-            } else if take_ab_suffix {
-                path[..path.len() - 1].to_owned()
-            } else {
-                path.to_owned()
-            };
-            // Transform path into a valid Rust identifier
-            let name = path.replace("/", "_").replace("-", "_");
-            Some((name, path))
-        })
-}
-
-#[derive(Clone)]
-struct TestFeature {
-    /// Name of the module, used in the output of `cargo test`
-    module_name: &'static str,
-    /// Directory containing the tests files, relative to the base tests directory
-    directory: &'static str,
-    /// Relevant variant of `dhall::tests::Test`
-    variant: &'static str,
-    /// Given a file name, whether to only include it in release tests
-    too_slow_path: Rc<dyn Fn(&str) -> bool>,
-    /// Given a file name, whether to exclude it
-    exclude_path: Rc<dyn Fn(&str) -> bool>,
-    /// Type of the input file
-    input_type: FileType,
-    /// Type of the output file, if any
-    output_type: Option<FileType>,
-}
-
-fn make_test_module(
-    w: &mut impl Write, // Where to output the generated code
-    base_paths: &[&Path],
-    feature: TestFeature,
-) -> std::io::Result<()> {
-    writeln!(w, "mod {} {{", feature.module_name)?;
-    let take_ab_suffix = feature.output_type.is_some()
-        && (feature.output_type != Some(FileType::UI)
-            || feature.module_name == "printer");
-    let input_suffix = if take_ab_suffix { "A" } else { "" };
-    let output_suffix = if take_ab_suffix { "B" } else { "" };
-
-    for base_path in base_paths {
-        let tests_dir = base_path.join(feature.directory);
-        for (name, path) in
-            dhall_files_in_dir(&tests_dir, take_ab_suffix, feature.input_type)
-        {
-            if (feature.exclude_path)(&path) {
-                continue;
-            }
-            if (feature.too_slow_path)(&path) {
-                writeln!(w, "#[cfg(not(debug_assertions))]")?;
-            }
-            let path = tests_dir.join(path);
-            let path = path.to_string_lossy();
-
-            let input = feature
-                .input_type
-                .construct(&format!("{}{}", path, input_suffix));
-            let output = match feature.output_type {
-                None => None,
-                Some(output_type @ FileType::UI) => {
-                    // All ui outputs are in the local `tests/` directory.
-                    let path = PathBuf::from("tests/").join(
-                        PathBuf::from(path.as_ref())
-                            .strip_prefix(base_path)
-                            .unwrap(),
-                    );
-                    let path = path.to_str().unwrap();
-                    let output = output_type
-                        .construct(&format!("{}{}", path, output_suffix));
-                    Some(output)
-                }
-                Some(output_type) => {
-                    let output = output_type
-                        .construct(&format!("{}{}", path, output_suffix));
-                    Some(output)
-                }
-            };
-
-            let test = match output {
-                None => format!("{}({})", feature.variant, input),
-                Some(output) => {
-                    format!("{}({}, {})", feature.variant, input, output)
-                }
-            };
-            writeln!(w, "make_spec_test!({}, {});", test, name)?;
-        }
-    }
-    writeln!(w, "}}")?;
-    Ok(())
-}
-
-fn generate_tests() -> std::io::Result<()> {
-    // To force regeneration of the test list, `touch dhall/build.rs`
-    let out_dir = env::var("OUT_DIR").unwrap();
-
-    let parser_tests_path = Path::new(&out_dir).join("spec_tests.rs");
-    let spec_tests_dirs =
-        vec![Path::new("../dhall-lang/tests/"), Path::new("tests/")];
-
-    let default_feature = TestFeature {
-        module_name: "",
-        directory: "",
-        variant: "",
-        too_slow_path: Rc::new(|_path: &str| false),
-        exclude_path: Rc::new(|_path: &str| false),
-        input_type: FileType::Text,
-        output_type: None,
-    };
-
-    #[allow(clippy::nonminimal_bool)]
-    let tests = vec![
-        TestFeature {
-            module_name: "parser_success",
-            directory: "parser/success/",
-            variant: "ParserSuccess",
-            too_slow_path: Rc::new(|path: &str| path == "largeExpression"),
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // Pretty sure the test is incorrect
-                    || path == "unit/import/urls/quotedPathFakeUrlEncode"
-            }),
-            output_type: Some(FileType::Binary),
-            ..default_feature
-        },
-        TestFeature {
-            module_name: "parser_failure",
-            directory: "parser/failure/",
-            variant: "ParserFailure",
-            output_type: Some(FileType::UI),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "printer",
-            directory: "parser/success/",
-            variant: "Printer",
-            too_slow_path: Rc::new(|path: &str| path == "largeExpression"),
-            output_type: Some(FileType::UI),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "binary_encoding",
-            directory: "parser/success/",
-            variant: "BinaryEncoding",
-            too_slow_path: Rc::new(|path: &str| path == "largeExpression"),
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // Pretty sure the test is incorrect
-                    || path == "unit/import/urls/quotedPathFakeUrlEncode"
-                    // See https://github.com/pyfisch/cbor/issues/109
-                    || path == "double"
-                    || path == "unit/DoubleLitExponentNoDot"
-                    || path == "unit/DoubleLitSecretelyInt"
-            }),
-            output_type: Some(FileType::Binary),
-            ..default_feature
-        },
-        TestFeature {
-            module_name: "binary_decoding_success",
-            directory: "binary-decode/success/",
-            variant: "BinaryDecodingSuccess",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // We don't support bignums
-                    || path == "unit/IntegerBigNegative"
-                    || path == "unit/IntegerBigPositive"
-                    || path == "unit/NaturalBig"
-            }),
-            input_type: FileType::Binary,
-            output_type: Some(FileType::Text),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "binary_decoding_failure",
-            directory: "binary-decode/failure/",
-            variant: "BinaryDecodingFailure",
-            input_type: FileType::Binary,
-            output_type: Some(FileType::UI),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "import_success",
-            directory: "import/success/",
-            variant: "ImportSuccess",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // TODO: the standard does not respect https://tools.ietf.org/html/rfc3986#section-5.2
-                    || path == "unit/asLocation/RemoteCanonicalize4"
-                    // TODO: import headers
-                    || path == "customHeaders"
-                    || path == "headerForwarding"
-                    || path == "noHeaderForwarding"
-            }),
-            output_type: Some(FileType::Text),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "import_failure",
-            directory: "import/failure/",
-            variant: "ImportFailure",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // TODO: import headers
-                    || path == "customHeadersUsingBoundVariable"
-            }),
-            output_type: Some(FileType::UI),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "semantic_hash",
-            directory: "semantic-hash/success/",
-            variant: "SemanticHash",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // We don't support bignums
-                    || path == "simple/integerToDouble"
-                    // See https://github.com/pyfisch/cbor/issues/109
-                    || path == "prelude/Integer/toDouble/0"
-                    || path == "prelude/Integer/toDouble/1"
-                    || path == "prelude/Natural/toDouble/0"
-            }),
-            output_type: Some(FileType::Hash),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "beta_normalize",
-            directory: "normalization/success/",
-            variant: "Normalization",
-            too_slow_path: Rc::new(|path: &str| path == "remoteSystems"),
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // Cannot typecheck
-                    || path == "unit/Sort"
-                    // We don't support bignums
-                    || path == "simple/integerToDouble"
-                    // TODO: fix Double/show
-                    || path == "prelude/JSON/number/1"
-            }),
-            output_type: Some(FileType::Text),
-            ..default_feature
-        },
-        TestFeature {
-            module_name: "alpha_normalize",
-            directory: "alpha-normalization/success/",
-            variant: "AlphaNormalization",
-            exclude_path: Rc::new(|path: &str| {
-                // This test is designed to not typecheck
-                path == "unit/FunctionNestedBindingXXFree"
-            }),
-            output_type: Some(FileType::Text),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "type_inference_success",
-            directory: "type-inference/success/",
-            variant: "TypeInferenceSuccess",
-            too_slow_path: Rc::new(|path: &str| path == "prelude"),
-            output_type: Some(FileType::Text),
-            ..default_feature.clone()
-        },
-        TestFeature {
-            module_name: "type_inference_failure",
-            directory: "type-inference/failure/",
-            variant: "TypeInferenceFailure",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // TODO: enable free variable checking
-                    || path == "unit/MergeHandlerFreeVar"
-            }),
-            output_type: Some(FileType::UI),
-            ..default_feature
-        },
-    ];
-
-    let mut file = File::create(parser_tests_path)?;
-    for test in tests {
-        make_test_module(&mut file, &spec_tests_dirs, test)?;
-    }
-
-    Ok(())
-}
-
 fn convert_abnf_to_pest() -> std::io::Result<()> {
     let out_dir = env::var("OUT_DIR").unwrap();
     let abnf_path = "src/syntax/text/dhall.abnf";
@@ -476,6 +135,5 @@ fn generate_pest_parser() -> std::io::Result<()> {
 fn main() -> std::io::Result<()> {
     convert_abnf_to_pest()?;
     generate_pest_parser()?;
-    generate_tests()?;
     Ok(())
 }
diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs
index 73f0b74..bda31d5 100644
--- a/dhall/src/lib.rs
+++ b/dhall/src/lib.rs
@@ -8,8 +8,6 @@
     clippy::useless_format
 )]
 
-mod tests;
-
 pub mod builtins;
 pub mod error;
 pub mod operations;
diff --git a/dhall/src/tests.rs b/dhall/src/tests.rs
deleted file mode 100644
index c9ba377..0000000
--- a/dhall/src/tests.rs
+++ /dev/null
@@ -1,360 +0,0 @@
-#[cfg(not(test))]
-use assert_eq as assert_eq_pretty;
-#[cfg(test)]
-use pretty_assertions::assert_eq as assert_eq_pretty;
-
-use std::env;
-use std::fmt::Display;
-use std::fs::{create_dir_all, read_to_string, File};
-use std::io::{Read, Write};
-use std::path::PathBuf;
-
-use crate::error::{ErrorKind, Result};
-use crate::syntax::{binary, Expr};
-use crate::{Normalized, Parsed, Resolved, Typed};
-
-macro_rules! assert_eq_display {
-    ($left:expr, $right:expr) => {{
-        match (&$left, &$right) {
-            (left_val, right_val) => {
-                if !(*left_val == *right_val) {
-                    panic!(
-                        r#"assertion failed: `(left == right)`
- left: `{}`,
-right: `{}`"#,
-                        left_val, right_val
-                    )
-                }
-            }
-        }
-    }};
-}
-
-/// Wrapper around string slice that makes debug output `{:?}` to print string same way as `{}`.
-/// Used in different `assert*!` macros in combination with `pretty_assertions` crate to make
-/// test failures to show nice diffs.
-#[derive(PartialEq, Eq)]
-#[doc(hidden)]
-pub struct PrettyString(String);
-
-/// Make diff to display string as multi-line string
-impl std::fmt::Debug for PrettyString {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        f.write_str(&self.0)
-    }
-}
-
-macro_rules! assert_eq_pretty_str {
-    ($left:expr, $right:expr) => {
-        assert_eq_pretty!(
-            PrettyString($left.to_string()),
-            PrettyString($right.to_string())
-        );
-    };
-}
-
-#[allow(dead_code)]
-enum Test {
-    ParserSuccess(TestFile, TestFile),
-    ParserFailure(TestFile, TestFile),
-    Printer(TestFile, TestFile),
-    BinaryEncoding(TestFile, TestFile),
-    BinaryDecodingSuccess(TestFile, TestFile),
-    BinaryDecodingFailure(TestFile, TestFile),
-    ImportSuccess(TestFile, TestFile),
-    ImportFailure(TestFile, TestFile),
-    SemanticHash(TestFile, TestFile),
-    TypeInferenceSuccess(TestFile, TestFile),
-    TypeInferenceFailure(TestFile, TestFile),
-    Normalization(TestFile, TestFile),
-    AlphaNormalization(TestFile, TestFile),
-}
-
-#[allow(dead_code)]
-enum TestFile {
-    Source(&'static str),
-    Binary(&'static str),
-    UI(&'static str),
-}
-
-impl TestFile {
-    pub fn path(&self) -> PathBuf {
-        match self {
-            TestFile::Source(path)
-            | TestFile::Binary(path)
-            | TestFile::UI(path) => PathBuf::from("dhall").join(path),
-        }
-    }
-
-    /// Parse the target file
-    pub fn parse(&self) -> Result<Parsed> {
-        match self {
-            TestFile::Source(_) => Parsed::parse_file(&self.path()),
-            TestFile::Binary(_) => Parsed::parse_binary_file(&self.path()),
-            TestFile::UI(_) => panic!("Can't parse a UI test file"),
-        }
-    }
-    /// Parse and resolve the target file
-    pub fn resolve(&self) -> Result<Resolved> {
-        Ok(self.parse()?.resolve()?)
-    }
-    /// Parse, resolve and tck the target file
-    pub fn typecheck(&self) -> Result<Typed> {
-        Ok(self.resolve()?.typecheck()?)
-    }
-    /// Parse, resolve, tck and normalize the target file
-    pub fn normalize(&self) -> Result<Normalized> {
-        Ok(self.typecheck()?.normalize())
-    }
-
-    /// If UPDATE_TEST_FILES=1, we overwrite the output files with our own output.
-    fn force_update() -> bool {
-        env::var("UPDATE_TEST_FILES") == Ok("1".to_string())
-    }
-    /// Write the provided expression to the pointed file.
-    fn write_expr(&self, expr: impl Into<Expr>) -> Result<()> {
-        let expr = expr.into();
-        let path = self.path();
-        create_dir_all(path.parent().unwrap())?;
-        let mut file = File::create(path)?;
-        match self {
-            TestFile::Source(_) => {
-                writeln!(file, "{}", expr)?;
-            }
-            TestFile::Binary(_) => {
-                let expr_data = binary::encode(&expr)?;
-                file.write_all(&expr_data)?;
-            }
-            TestFile::UI(_) => panic!("Can't write an expression to a UI file"),
-        }
-        Ok(())
-    }
-    /// Write the provided string to the pointed file.
-    fn write_ui(&self, x: impl Display) -> Result<()> {
-        match self {
-            TestFile::UI(_) => {}
-            _ => panic!("Can't write a ui string to a dhall file"),
-        }
-        let path = self.path();
-        create_dir_all(path.parent().unwrap())?;
-        let mut file = File::create(path)?;
-        writeln!(file, "{}", x)?;
-        Ok(())
-    }
-
-    /// Check that the provided expression matches the file contents.
-    pub fn compare(&self, expr: impl Into<Expr>) -> Result<()> {
-        let expr = expr.into();
-        if !self.path().is_file() {
-            return self.write_expr(expr);
-        }
-
-        let expected = self.parse()?.to_expr();
-        if expr != expected {
-            if Self::force_update() {
-                self.write_expr(expr)?;
-            } else {
-                assert_eq_display!(expr, expected);
-            }
-        }
-        Ok(())
-    }
-    /// Check that the provided expression matches the file contents.
-    pub fn compare_debug(&self, expr: impl Into<Expr>) -> Result<()> {
-        let expr = expr.into();
-        if !self.path().is_file() {
-            return self.write_expr(expr);
-        }
-
-        let expected = self.parse()?.to_expr();
-        if expr != expected {
-            if Self::force_update() {
-                self.write_expr(expr)?;
-            } else {
-                assert_eq_pretty!(expr, expected);
-            }
-        }
-        Ok(())
-    }
-    /// Check that the provided expression matches the file contents.
-    pub fn compare_binary(&self, expr: impl Into<Expr>) -> Result<()> {
-        let expr = expr.into();
-        match self {
-            TestFile::Binary(_) => {}
-            _ => panic!("This is not a binary file"),
-        }
-        if !self.path().is_file() {
-            return self.write_expr(expr);
-        }
-
-        let expr_data = binary::encode(&expr)?;
-        let expected_data = {
-            let mut data = Vec::new();
-            File::open(&self.path())?.read_to_end(&mut data)?;
-            data
-        };
-
-        // Compare bit-by-bit
-        if expr_data != expected_data {
-            if Self::force_update() {
-                self.write_expr(expr)?;
-            } else {
-                use serde_cbor::de::from_slice;
-                use serde_cbor::value::Value;
-                // Pretty-print difference
-                assert_eq_pretty!(
-                    from_slice::<Value>(&expr_data).unwrap(),
-                    from_slice::<Value>(&expected_data).unwrap()
-                );
-                // If difference was not visible in the cbor::Nir, compare normally.
-                assert_eq!(expr_data, expected_data);
-            }
-        }
-        Ok(())
-    }
-    /// Check that the provided string matches the file contents. Writes to the corresponding file
-    /// if it is missing.
-    pub fn compare_ui(&self, x: impl Display) -> Result<()> {
-        if !self.path().is_file() {
-            return self.write_ui(x);
-        }
-
-        let expected = read_to_string(self.path())?;
-        let msg = format!("{}\n", x);
-        if msg != expected {
-            if Self::force_update() {
-                self.write_ui(x)?;
-            } else {
-                assert_eq_pretty_str!(expected, msg);
-            }
-        }
-        Ok(())
-    }
-}
-
-#[allow(dead_code)]
-fn run_test_or_panic(test: Test) {
-    let res = if env::var("CI_GRCOV").is_ok() {
-        // Augment stack size when running with 0 inlining to avoid overflows
-        std::thread::Builder::new()
-            .stack_size(128 * 1024 * 1024)
-            .spawn(|| run_test(test))
-            .unwrap()
-            .join()
-            .unwrap()
-    } else {
-        run_test(test)
-    };
-    match res {
-        Ok(_) => {}
-        Err(e) => panic!(e.to_string()),
-    }
-}
-
-fn run_test(test: Test) -> Result<()> {
-    use self::Test::*;
-    // Setup current directory to the root of the repository. Important for `as Location` tests.
-    let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .parent()
-        .unwrap()
-        .to_path_buf();
-    env::set_current_dir(root_dir.as_path())?;
-    // Set environment variable for import tests.
-    env::set_var("DHALL_TEST_VAR", "6 * 7");
-
-    match test {
-        ParserSuccess(expr, expected) => {
-            let expr = expr.parse()?;
-            // This exercices both parsing and binary decoding
-            expected.compare_debug(expr)?;
-        }
-        ParserFailure(expr, expected) => {
-            use std::io;
-            let err = expr.parse().unwrap_err();
-            match err.kind() {
-                ErrorKind::Parse(_) => {}
-                ErrorKind::IO(e) if e.kind() == io::ErrorKind::InvalidData => {}
-                e => panic!("Expected parse error, got: {:?}", e),
-            }
-            expected.compare_ui(err)?;
-        }
-        BinaryEncoding(expr, expected) => {
-            let expr = expr.parse()?;
-            expected.compare_binary(expr)?;
-        }
-        BinaryDecodingSuccess(expr, expected) => {
-            let expr = expr.parse()?;
-            expected.compare_debug(expr)?;
-        }
-        BinaryDecodingFailure(expr, expected) => {
-            let err = expr.parse().unwrap_err();
-            expected.compare_ui(err)?;
-        }
-        Printer(expr, expected) => {
-            let parsed = expr.parse()?;
-            // Round-trip pretty-printer
-            let reparsed = Parsed::parse_str(&parsed.to_string())?;
-            assert_eq!(reparsed, parsed);
-            expected.compare_ui(parsed)?;
-        }
-        ImportSuccess(expr, expected) => {
-            // Configure cache for import tests
-            env::set_var(
-                "XDG_CACHE_HOME",
-                root_dir
-                    .join("dhall-lang")
-                    .join("tests")
-                    .join("import")
-                    .join("cache")
-                    .as_path(),
-            );
-            let expr = expr.normalize()?;
-            expected.compare(expr)?;
-        }
-        ImportFailure(expr, expected) => {
-            let err = expr.resolve().unwrap_err();
-            expected.compare_ui(err)?;
-        }
-        SemanticHash(expr, expected) => {
-            let expr = expr.normalize()?.to_expr_alpha();
-            let hash = hex::encode(expr.hash()?);
-            expected.compare_ui(format!("sha256:{}", hash))?;
-        }
-        TypeInferenceSuccess(expr, expected) => {
-            let ty = expr.typecheck()?.get_type()?;
-            expected.compare(ty)?;
-        }
-        TypeInferenceFailure(expr, expected) => {
-            let err = expr.typecheck().unwrap_err();
-            expected.compare_ui(err)?;
-        }
-        Normalization(expr, expected) => {
-            let expr = expr.normalize()?;
-            expected.compare(expr)?;
-        }
-        AlphaNormalization(expr, expected) => {
-            let expr = expr.normalize()?.to_expr_alpha();
-            expected.compare(expr)?;
-        }
-    }
-
-    Ok(())
-}
-
-#[cfg(test)]
-mod spec {
-    macro_rules! make_spec_test {
-        ($type:expr, $name:ident) => {
-            #[test]
-            #[allow(non_snake_case)]
-            fn $name() {
-                use crate::tests::Test::*;
-                use crate::tests::*;
-                run_test_or_panic($type);
-            }
-        };
-    }
-
-    // See build.rs
-    // include!(concat!(env!("OUT_DIR"), "/spec_tests.rs"));
-}
diff --git a/dhall/tests/spec.rs b/dhall/tests/spec.rs
index ca09ef0..628f084 100644
--- a/dhall/tests/spec.rs
+++ b/dhall/tests/spec.rs
@@ -470,8 +470,6 @@ fn define_features() -> Vec<TestFeature> {
             variant: SpecTestKind::ImportSuccess,
             exclude_path: Rc::new(|path: &str| {
                 false
-                    // TODO: import hash
-                    || path == "hashFromCache"
                     // TODO: the standard does not respect https://tools.ietf.org/html/rfc3986#section-5.2
                     || path == "unit/asLocation/RemoteCanonicalize4"
                     // TODO: import headers
@@ -579,9 +577,11 @@ fn run_test_or_panic(test: &SpecTest) {
 fn run_test(test: &SpecTest) -> Result<()> {
     use self::SpecTestKind::*;
     // Setup current directory to the root of the repository. Important for `as Location` tests.
-    env::set_current_dir(
-        PathBuf::from(env!("CARGO_MANIFEST_DIR")).parent().unwrap(),
-    )?;
+    let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .parent()
+        .unwrap()
+        .to_path_buf();
+    env::set_current_dir(root_dir.as_path())?;
     // Set environment variable for import tests.
     env::set_var("DHALL_TEST_VAR", "6 * 7");
 
@@ -626,6 +626,16 @@ fn run_test(test: &SpecTest) -> Result<()> {
             expected.compare_ui(parsed)?;
         }
         ImportSuccess => {
+            // Configure cache for import tests
+            env::set_var(
+                "XDG_CACHE_HOME",
+                root_dir
+                    .join("dhall-lang")
+                    .join("tests")
+                    .join("import")
+                    .join("cache")
+                    .as_path(),
+            );
             let expr = expr.normalize()?;
             expected.compare(expr)?;
         }