Add support for merge keys and aliases in YAML (#531)

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to MiniJinja are documented here.
   `str.isalnum`, `str.isalpha`, `str.isascii`, `str.isdigit`,
   `str.isnumeric`, `str.join`, `str.startswith`.  #522
 - Added the missing tests `boolean`, `divisibleby`, `lower` and `upper`.  #592
+- minijinja-cli now supports YAML aliases and merge keys.  #531
 
 ## 2.0.2
 

minijinja-cli/Cargo.toml

@@ -13,7 +13,7 @@ rust-version = "1.65"
 
 [features]
 default = ["toml", "yaml", "querystring", "cbor", "datetime", "json5", "repl", "unicode"]
-yaml = ["serde_yaml"]
+yaml = ["serde_yml"]
 querystring = ["serde_qs"]
 cbor = ["ciborium"]
 datetime = ["minijinja-contrib/datetime", "minijinja-contrib/timezone"]
@@ -47,7 +47,7 @@ serde = "1.0.183"
 serde_json = "1.0.105"
 serde_json5 = { version = "0.1.0", optional = true }
 serde_qs = { version = "0.12.0", optional = true }
-serde_yaml = { version = "0.9.25", optional = true }
+serde_yml = { version = "0.0.10", optional = true }
 tempfile = "3.9.0"
 toml = { version = "0.7.6", optional = true }
 clap_complete = { version = "4", optional = true }

minijinja-cli/examples/alias.j2

@@ -0,0 +1 @@
+{{ dict3 }}

minijinja-cli/examples/alias.yaml

@@ -0,0 +1,9 @@
+dict1: &dict1_anchor
+  key1: value1
+
+dict2: &dict2_anchor
+  key2: value2
+
+dict3:
+  <<: [*dict1_anchor, *dict2_anchor]
+  key3: value3

minijinja-cli/examples/dump.j2

@@ -0,0 +1 @@
+{{ debug() }}

minijinja-cli/src/main.rs

@@ -116,7 +116,14 @@ fn load_data(
         #[cfg(feature = "querystring")]
         "querystring" => Value::from(serde_qs::from_str::<HashMap<String, Value>>(&contents)?),
         #[cfg(feature = "yaml")]
-        "yaml" => serde_yaml::from_str(&contents)?,
+        "yaml" => {
+            // for merge keys to work we need to manually call `apply_merge`.
+            // For this reason we need to deserialize into a serde_yml::Value
+            // before converting it into a final value.
+            let mut v: serde_yml::Value = serde_yml::from_str(&contents)?;
+            v.apply_merge()?;
+            Value::from_serialize(v)
+        }
         #[cfg(feature = "toml")]
         "toml" => toml::from_str(&contents)?,
         #[cfg(feature = "cbor")]
@@ -157,7 +164,7 @@ fn interpret_raw_value(s: &str) -> Result<Value, Error> {
     }
     #[cfg(feature = "yaml")]
     mod imp {
-        pub use serde_yaml::from_str;
+        pub use serde_yml::from_str;
         pub const FMT: &str = "JSON";
     }
     imp::from_str::<Value>(s)

minijinja-cli/tests/test_basic.rs

@@ -138,6 +138,43 @@ fn test_yaml() {
     "###);
 }
 
+#[test]
+#[cfg(feature = "yaml")]
+fn test_yaml_aliases() {
+    let input = file_with_contents_and_ext(
+        r#"
+a: &a
+  key1: value1
+
+b: &b
+  key2: value2
+
+c:
+  <<: *a
+  key2: from-c
+
+d:
+  <<: [*a, *b]
+  key3: value3
+"#,
+        ".yaml",
+    );
+    let tmpl = file_with_contents(r#"{{ [c.key1, c.key2] }}\n{{ [d.key1, d.key2, d.key3] }}"#);
+
+    assert_cmd_snapshot!(
+        cli()
+            .arg(tmpl.path())
+            .arg(input.path()),
+        @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    ["value1", "from-c"]\n["value1", "value2", "value3"]
+
+    ----- stderr -----
+    "###);
+}
+
 #[test]
 #[cfg(feature = "toml")]
 fn test_toml() {