refactor: extract a crate with our custom assertions

There's probably an existing crate that we should use directly, but I
haven't found an exact match yet.

Cargo.lock

@@ -373,6 +373,7 @@ dependencies = [
  "criterion 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "croaring 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "csv 1.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "delorean_test_helpers 0.1.0",
  "dirs 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "dotenv 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -400,6 +401,10 @@ dependencies = [
  "tonic-build 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "delorean_test_helpers"
+version = "0.1.0"
+
 [[package]]
 name = "delorean_utilities"
 version = "0.1.0"

Cargo.toml

@@ -6,7 +6,10 @@ edition = "2018"
 default-run = "delorean"
 
 [workspace]
-members = ["delorean_utilities"]
+members = [
+    "delorean_test_helpers",
+    "delorean_utilities",
+]
 
 [profile.release]
 debug = true
@@ -52,6 +55,7 @@ either = "1.5.3"
 smallvec = "1.2.0"
 
 [dev-dependencies]
+delorean_test_helpers = { path = "delorean_test_helpers" }
 criterion = "0.3"
 assert_cmd = "1.0.0"
 tempfile = "3.1.0"

delorean_test_helpers/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "delorean_test_helpers"
+version = "0.1.0"
+authors = ["Paul Dix <paul@pauldix.net>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

delorean_test_helpers/src/lib.rs

@@ -0,0 +1,8 @@
+use std::f64;
+
+/// A test helper function for asserting floating point numbers are within the machine epsilon
+/// because strict comparison of floating point numbers is incorrect
+pub fn approximately_equal(f1: f64, f2: f64) -> bool {
+    (f1 - f2).abs() < f64::EPSILON
+}
+

src/encoders/float.rs

@@ -491,7 +491,7 @@ pub fn decode(src: &[u8], dst: &mut Vec<f64>) -> Result<(), Box<dyn Error>> {
 #[allow(clippy::unreadable_literal)]
 #[allow(clippy::excessive_precision)] // TODO: Audit test values for truncation
 mod tests {
-    use crate::tests::approximately_equal;
+    use delorean_test_helpers::approximately_equal;
 
     #[test]
     fn encode_no_values() {

src/lib.rs

@@ -32,14 +32,3 @@ impl error::Error for Error {
         None
     }
 }
-
-#[cfg(test)]
-pub mod tests {
-    use std::f64;
-
-    /// A test helper function for asserting floating point numbers are within the machine epsilon
-    /// because strict comparison of floating point numbers is incorrect
-    pub fn approximately_equal(f1: f64, f2: f64) -> bool {
-        (f1 - f2).abs() < f64::EPSILON
-    }
-}

src/line_parser.rs

@@ -791,7 +791,7 @@ fn map_fail<'a, R1, R2>(
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::tests::approximately_equal;
+    use delorean_test_helpers::approximately_equal;
 
     type Error = Box<dyn std::error::Error>;
     type Result<T = (), E = Error> = std::result::Result<T, E>;

src/storage/block.rs

@@ -948,7 +948,7 @@ where
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::tests::approximately_equal;
+    use delorean_test_helpers::approximately_equal;
     use std::io::Cursor;
 
     #[test]