Add chain properties to chain-spec-builder (#7368)

This PR adds support for chain properties to `chain-spec-builder`. Now
properties can be specified as such:

```sh
$ chain-spec-builder create -r $RUNTIME_PATH --properties tokenSymbol=DUMMY,tokenDecimals=6,isEthereum=false
```

---------

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Michal Kucharczyk <[email protected]>

Author: 3 people

prdoc/pr_7368.prdoc

@@ -0,0 +1,13 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: "Add chain properties to chain-spec-builder"
+
+doc:
+  - audience: Node Dev
+    description: |
+      - Adds support for chain properties to chain-spec-builder.
+
+crates:
+  - name: staging-chain-spec-builder
+    bump: minor

substrate/bin/utils/chain-spec-builder/src/lib.rs

@@ -83,6 +83,18 @@ pub struct CreateCmd {
 	/// errors will be reported.
 	#[arg(long, short = 'v')]
 	verify: bool,
+	/// Chain properties in `KEY=VALUE` format.
+	///
+	/// Multiple `KEY=VALUE` entries can be specified and separated by a comma.
+	///
+	/// Example: `--properties tokenSymbol=UNIT,tokenDecimals=12,ss58Format=42,isEthereum=false`
+	/// Or: `--properties tokenSymbol=UNIT --properties tokenDecimals=12 --properties ss58Format=42
+	/// --properties=isEthereum=false`
+	///
+	/// The first uses comma as separation and the second passes the argument multiple times. Both
+	/// styles can also be mixed.
+	#[arg(long, default_value = "tokenSymbol=UNIT,tokenDecimals=12")]
+	pub properties: Vec<String>,
 	#[command(subcommand)]
 	action: GenesisBuildAction,
 
@@ -385,15 +397,44 @@ impl CreateCmd {
 	}
 }
 
-/// Processes `CreateCmd` and returns string represenataion of JSON version of `ChainSpec`.
+/// Parses chain properties passed as a comma-separated KEY=VALUE pairs.
+fn parse_properties(raw: &String, props: &mut sc_chain_spec::Properties) -> Result<(), String> {
+	for pair in raw.split(',') {
+		let mut iter = pair.splitn(2, '=');
+		let key = iter
+			.next()
+			.ok_or_else(|| format!("Invalid chain property key: {pair}"))?
+			.trim()
+			.to_owned();
+		let value_str = iter
+			.next()
+			.ok_or_else(|| format!("Invalid chain property value for key: {key}"))?
+			.trim();
+
+		// Try to parse as bool, number, or fallback to String
+		let value = match value_str.parse::<bool>() {
+			Ok(b) => Value::Bool(b),
+			Err(_) => match value_str.parse::<u32>() {
+				Ok(i) => Value::Number(i.into()),
+				Err(_) => Value::String(value_str.to_string()),
+			},
+		};
+
+		props.insert(key, value);
+	}
+	Ok(())
+}
+
+/// Processes `CreateCmd` and returns string representation of JSON version of `ChainSpec`.
 pub fn generate_chain_spec_for_runtime(cmd: &CreateCmd) -> Result<String, String> {
 	let code = cmd.get_runtime_code()?;
 
 	let chain_type = &cmd.chain_type;
 
 	let mut properties = sc_chain_spec::Properties::new();
-	properties.insert("tokenSymbol".into(), "UNIT".into());
-	properties.insert("tokenDecimals".into(), 12.into());
+	for raw in &cmd.properties {
+		parse_properties(raw, &mut properties)?;
+	}
 
 	let builder = ChainSpec::builder(&code[..], Default::default())
 		.with_name(&cmd.chain_name[..])

substrate/bin/utils/chain-spec-builder/tests/expected/create_with_properties.json

@@ -0,0 +1,40 @@
+{
+  "name": "Custom",
+  "id": "custom",
+  "chainType": "Live",
+  "bootNodes": [],
+  "telemetryEndpoints": null,
+  "protocolId": null,
+  "properties": {
+    "tokenDecimals": 6,
+    "tokenSymbol": "TEST",
+    "ss58Prefix": 42,
+    "isEthereum": false
+  },
+  "codeSubstitutes": {},
+  "genesis": {
+    "runtimeGenesis": {
+      "code": "0x010203",
+      "config": {
+        "babe": {
+          "authorities": [],
+          "epochConfig": {
+            "allowed_slots": "PrimaryAndSecondaryVRFSlots",
+            "c": [
+              1,
+              4
+            ]
+          }
+        },
+        "balances": {
+          "balances": [],
+          "devAccounts": null
+        },
+        "substrateTest": {
+          "authorities": []
+        },
+        "system": {}
+      }
+    }
+  }
+}

substrate/bin/utils/chain-spec-builder/tests/test.rs

@@ -234,6 +234,29 @@ fn test_add_code_substitute() {
 	assert_output_eq_expected(true, SUFFIX, "tests/expected/add_code_substitute.json");
 }
 
+#[test]
+fn test_create_with_properties() {
+	const SUFFIX: &str = "11";
+	let mut builder = get_builder(
+		SUFFIX,
+		vec![
+			"create",
+			"-r",
+			DUMMY_PATH,
+			"--properties",
+			"tokenSymbol=TEST,tokenDecimals=6",
+			"--properties",
+			"isEthereum=false",
+			"--properties",
+			"ss58Prefix=42",
+			"default",
+		],
+	);
+	builder.set_create_cmd_runtime_code(substrate_test_runtime::WASM_BINARY.unwrap().into());
+	builder.run().unwrap();
+	assert_output_eq_expected(true, SUFFIX, "tests/expected/create_with_properties.json");
+}
+
 #[docify::export_content]
 fn cmd_create_default(runtime_path: &str) -> String {
 	bash!(