Add meili-snap crate to make writing snapshot tests easier

.gitignore

@@ -7,3 +7,10 @@
 /data.ms
 /snapshots
 /dumps
+
+
+# Snapshots
+## ... large
+*.full.snap
+##  ... unreviewed
+*.snap.new

Cargo.lock

@@ -2242,6 +2242,21 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
 
+[[package]]
+name = "md5"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "490cc448043f947bae3cbee9c203358d62dbee0db12107a74be5c30ccfd09771"
+
+[[package]]
+name = "meili-snap"
+version = "0.1.0"
+dependencies = [
+ "insta",
+ "md5",
+ "once_cell",
+]
+
 [[package]]
 name = "meilisearch-auth"
 version = "0.29.1"

Cargo.toml

@@ -4,6 +4,7 @@ members = [
     "meilisearch-http",
     "meilisearch-types",
     "meilisearch-auth",
+    "meili-snap",
     "index-scheduler",
     "dump",
     "file-store",

meili-snap/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "meili-snap"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+insta = { version = "1.19.1", features = ["json", "redactions"] }
+md5 = "0.7.0"
+once_cell = "1.15"

meili-snap/src/lib.rs

@@ -0,0 +1,229 @@
+use once_cell::sync::Lazy;
+use std::borrow::Cow;
+use std::path::PathBuf;
+use std::sync::Mutex;
+use std::{collections::HashMap, path::Path};
+
+static SNAPSHOT_NAMES: Lazy<Mutex<HashMap<PathBuf, usize>>> = Lazy::new(|| Mutex::default());
+
+/// Return the md5 hash of the given string
+pub fn hash_snapshot(snap: &str) -> String {
+    let hash = md5::compute(snap.as_bytes());
+    let hash_str = format!("{hash:x}");
+    hash_str
+}
+
+#[track_caller]
+pub fn default_snapshot_settings_for_test(name: Option<&str>) -> (insta::Settings, Cow<'_, str>) {
+    let mut settings = insta::Settings::clone_current();
+    settings.set_prepend_module_to_snapshot(false);
+    let path = Path::new(std::panic::Location::caller().file());
+    let filename = path.file_name().unwrap().to_str().unwrap();
+    settings.set_omit_expression(true);
+
+    let test_name = std::thread::current()
+        .name()
+        .unwrap()
+        .rsplit("::")
+        .next()
+        .unwrap()
+        .to_owned();
+
+    let path = Path::new("snapshots")
+        .join(filename)
+        .join(&test_name)
+        .to_owned();
+    settings.set_snapshot_path(path.clone());
+    let snap_name = if let Some(name) = name {
+        Cow::Borrowed(name)
+    } else {
+        let mut snapshot_names = SNAPSHOT_NAMES.lock().unwrap();
+        let counter = snapshot_names.entry(path).or_default();
+        *counter += 1;
+        Cow::Owned(format!("{counter}"))
+    };
+
+    (settings, snap_name)
+}
+
+/**
+Create a hashed snapshot test.
+
+## Arguments:
+
+1. The content of the snapshot. It is an expression whose result implements the `fmt::Display` trait.
+2. `name: <name>`: the identifier for the snapshot test (optional)
+3. `@""` to write the hash of the snapshot inline
+
+## Behaviour
+The content of the snapshot will be saved both in full and as a hash. The full snapshot will
+be saved with the name `<name>.full.snap` but will not be saved to the git repository. The hashed
+snapshot will be saved inline. If `<name>` is not specified, then a global counter is used to give an
+identifier to the snapshot.
+
+Running `cargo test` will check whether the old snapshot is identical to the
+current one. If they are equal, the test passes. Otherwise, the test fails.
+
+Use the command line `cargo insta` to approve or reject new snapshots.
+
+## Example
+```ignore
+// The full snapshot is saved under 1.full.snap and contains `10`
+snapshot_hash!(10, @"d3d9446802a44259755d38e6d163e820");
+// The full snapshot is saved under snap_name.full.snap and contains `hello world`
+snapshot_hash!("hello world", name: "snap_name", @"5f93f983524def3dca464469d2cf9f3e");
+```
+*/
+#[macro_export]
+macro_rules! snapshot_hash {
+    ($value:expr, @$inline:literal) => {
+        let (settings, snap_name) = $crate::default_snapshot_settings_for_test(None);
+        settings.bind(|| {
+            let snap = format!("{}", $value);
+            let hash_snap = $crate::hash_snapshot(&snap);
+            insta::assert_snapshot!(hash_snap, @$inline);
+            insta::assert_snapshot!(format!("{}.full", snap_name), snap);
+        });
+    };
+    ($value:expr, name: $name:expr, @$inline:literal) => {
+        let snap_name = format!("{}", $name);
+        let (settings, snap_name) = $crate::default_snapshot_settings_for_test(Some(&snap_name));
+        settings.bind(|| {
+            let snap = format!("{}", $value);
+            let hash_snap = $crate::hash_snapshot(&snap);
+            insta::assert_snapshot!(hash_snap, @$inline);
+            insta::assert_snapshot!(format!("{}.full", snap_name), snap);
+        });
+    };
+}
+
+/**
+Create a hashed snapshot test.
+
+## Arguments:
+1. The content of the snapshot. It is an expression whose result implements the `fmt::Display` trait.
+2. Optionally one of:
+    1. `name: <name>`: the identifier for the snapshot test
+    2. `@""` to write the hash of the snapshot inline
+
+## Behaviour
+The content of the snapshot will be saved in full with the given name
+or using a global counter to give it an identifier.
+
+Running `cargo test` will check whether the old snapshot is identical to the
+current one. If they are equal, the test passes. Otherwise, the test fails.
+
+Use the command line `cargo insta` to approve or reject new snapshots.
+
+## Example
+```ignore
+// The full snapshot is saved under 1.snap and contains `10`
+snapshot!(10);
+// The full snapshot is saved under snap_name.snap and contains `10`
+snapshot!("hello world", name: "snap_name");
+// The full snapshot is saved inline
+snapshot!(format!("{:?}", vec![1, 2]), @"[1, 2]");
+```
+*/
+#[macro_export]
+macro_rules! snapshot {
+    ($value:expr, name: $name:expr) => {
+        let snap_name = format!("{}", $name);
+        let (settings, snap_name) = $crate::default_snapshot_settings_for_test(Some(&snap_name));
+        settings.bind(|| {
+            let snap = format!("{}", $value);
+            insta::assert_snapshot!(format!("{}", snap_name), snap);
+        });
+    };
+    ($value:expr, @$inline:literal) => {
+        // Note that the name given as argument does not matter since it is only an inline snapshot
+        // We don't pass None because otherwise `meili-snap` will try to assign it a unique identifier
+        let (settings, _) = $crate::default_snapshot_settings_for_test(Some("_dummy_argument"));
+        settings.bind(|| {
+            let snap = format!("{}", $value);
+            insta::assert_snapshot!(snap, @$inline);
+        });
+    };
+    ($value:expr) => {
+        let (settings, snap_name) = $crate::default_snapshot_settings_for_test(None);
+        settings.bind(|| {
+            let snap = format!("{}", $value);
+            insta::assert_snapshot!(format!("{}", snap_name), snap);
+        });
+    };
+}
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn snap() {
+        snapshot_hash!(10, @"d3d9446802a44259755d38e6d163e820");
+        snapshot_hash!(20, @"98f13708210194c475687be6106a3b84");
+        snapshot_hash!(30, @"34173cb38f07f89ddbebc2ac9128303f");
+
+        snapshot!(40, @"40");
+        snapshot!(50, @"50");
+        snapshot!(60, @"60");
+
+        snapshot!(70);
+        snapshot!(80);
+        snapshot!(90);
+
+        snapshot!(100, name: "snap_name_1");
+        snapshot_hash!(110, name: "snap_name_2", @"5f93f983524def3dca464469d2cf9f3e");
+
+        snapshot!(120);
+        snapshot!(format!("{:?}", vec![1, 2]), @"[1, 2]");
+    }
+
+    // Currently the name of this module is not part of the snapshot path
+    // It does not bother me, but maybe it is worth changing later on.
+    mod snap {
+        #[test]
+        fn some_test() {
+            snapshot_hash!(10, @"d3d9446802a44259755d38e6d163e820");
+            snapshot_hash!(20, @"98f13708210194c475687be6106a3b84");
+            snapshot_hash!(30, @"34173cb38f07f89ddbebc2ac9128303f");
+
+            snapshot!(40, @"40");
+            snapshot!(50, @"50");
+            snapshot!(60, @"60");
+
+            snapshot!(70);
+            snapshot!(80);
+            snapshot!(90);
+
+            snapshot!(100, name: "snap_name_1");
+            snapshot_hash!(110, name: "snap_name_2", @"5f93f983524def3dca464469d2cf9f3e");
+
+            snapshot!(120);
+
+            snapshot_hash!("", name: "", @"d41d8cd98f00b204e9800998ecf8427e");
+        }
+    }
+}
+
+/// Create a string from the value by serializing it as Json, optionally
+/// redacting some parts of it.
+///
+/// The second argument to the macro can be an object expression for redaction.
+/// It's in the form { selector => replacement }. For more information about redactions
+/// refer to the redactions feature in the `insta` guide.
+#[macro_export]
+macro_rules! json_string {
+    ($value:expr, {$($k:expr => $v:expr),*$(,)?}) => {
+        {
+            let (_, snap) = insta::_prepare_snapshot_for_redaction!($value, {$($k => $v),*}, Json, File);
+            snap
+        }
+    };
+    ($value:expr) => {{
+        let value = insta::_macro_support::serialize_value(
+            &$value,
+            insta::_macro_support::SerializationFormat::Json,
+            insta::_macro_support::SnapshotLocation::File
+        );
+        value
+    }};
+}

meili-snap/src/snapshots/lib.rs/snap/4.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+70

meili-snap/src/snapshots/lib.rs/snap/5.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+80

meili-snap/src/snapshots/lib.rs/snap/6.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+90

meili-snap/src/snapshots/lib.rs/snap/7.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+120

meili-snap/src/snapshots/lib.rs/snap/snap_name_1.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+100

meili-snap/src/snapshots/lib.rs/some_test/4.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+70

meili-snap/src/snapshots/lib.rs/some_test/5.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+80

meili-snap/src/snapshots/lib.rs/some_test/6.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+90

meili-snap/src/snapshots/lib.rs/some_test/7.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+120

meili-snap/src/snapshots/lib.rs/some_test/snap_name_1.snap

@@ -0,0 +1,4 @@
+---
+source: meili-snap/src/lib.rs
+---
+100

meilisearch-http/src/option.rs

@@ -1,13 +1,11 @@
 use std::convert::TryFrom;
-use std::env;
-use std::fs;
 use std::io::{BufReader, Read};
 use std::num::ParseIntError;
 use std::ops::Deref;
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::sync::Arc;
-use std::{fmt, fs};
+use std::{env, fmt, fs};
 
 use byte_unit::{Byte, ByteError};
 use clap::Parser;
@@ -646,6 +644,17 @@ fn load_ocsp(filename: &Option<PathBuf>) -> anyhow::Result<Vec<u8>> {
     Ok(ret)
 }
 
+/// Checks if the key is defined in the environment variables.
+/// If not, inserts it with the given value.
+pub fn export_to_env_if_not_present<T>(key: &str, value: T)
+where
+    T: AsRef<OsStr>,
+{
+    if let Err(VarError::NotPresent) = std::env::var(key) {
+        std::env::set_var(key, value);
+    }
+}
+
 /// Functions used to get default value for `Opt` fields, needs to be function because of serde's default attribute.
 
 fn default_db_path() -> PathBuf {