test(selection): Refactor tests to reuse key strings

Previously, we had a string constants for test descriptors and test keys
where the test keys were also hardcoded in the test descriptors.

We remove the hard coded test descriptor and rename variables for
clarity.

Author: evanlinjin

src/selection.rs

@@ -356,16 +356,15 @@ mod tests {
     use miniscript::{plan::Assets, Descriptor, DescriptorPublicKey};
     use rand_core::OsRng;
 
-    const TEST_DESCRIPTOR: &str = "tr([83737d5e/86h/1h/0h]tpubDDR5GgtoxS8fJyjjvdahN4VzV5DV6jtbcyvVXhEKq2XtpxjxBXmxH3r8QrNbQqHg4bJM1EGkxi7Pjfkgnui9jQWqS7kxHvX6rhUeriLDKxz/0/*)";
-    const TEST_DESCRIPTOR_PK: &str = "[83737d5e/86h/1h/0h]tpubDDR5GgtoxS8fJyjjvdahN4VzV5DV6jtbcyvVXhEKq2XtpxjxBXmxH3r8QrNbQqHg4bJM1EGkxi7Pjfkgnui9jQWqS7kxHvX6rhUeriLDKxz/0/*";
-    const TEST_HEX_PK: &str = "032b0558078bec38694a84933d659303e2575dae7e91685911454115bfd64487e3";
+    const TEST_KEY_HEX: &str = "032b0558078bec38694a84933d659303e2575dae7e91685911454115bfd64487e3";
+    const TEST_KEY_TR: &str = "[83737d5e/86h/1h/0h]tpubDDR5GgtoxS8fJyjjvdahN4VzV5DV6jtbcyvVXhEKq2XtpxjxBXmxH3r8QrNbQqHg4bJM1EGkxi7Pjfkgnui9jQWqS7kxHvX6rhUeriLDKxz/0/*";
 
     fn setup_cltv_input(
         cltv: absolute::LockTime,
     ) -> anyhow::Result<(Input, Descriptor<DescriptorPublicKey>)> {
         let secp = Secp256k1::new();
-        let desc_str = format!("wsh(and_v(v:pk({TEST_HEX_PK}),after({cltv})))");
-        let desc_pk: DescriptorPublicKey = TEST_HEX_PK.parse()?;
+        let desc_str = format!("wsh(and_v(v:pk({TEST_KEY_HEX}),after({cltv})))");
+        let desc_pk: DescriptorPublicKey = TEST_KEY_HEX.parse()?;
         let (desc, _) = Descriptor::parse_descriptor(&secp, &desc_str)?;
         let plan = desc
             .at_derivation_index(0)?
@@ -483,12 +482,12 @@ mod tests {
 
     pub fn setup_test_input(confirmation_height: u32) -> anyhow::Result<Input> {
         let secp = Secp256k1::new();
-        let desc = Descriptor::parse_descriptor(&secp, TEST_DESCRIPTOR)
+        let desc = Descriptor::parse_descriptor(&secp, &format!("tr({TEST_KEY_TR})"))
             .unwrap()
             .0;
         let def_desc = desc.at_derivation_index(0).unwrap();
         let script_pubkey = def_desc.script_pubkey();
-        let desc_pk: DescriptorPublicKey = TEST_DESCRIPTOR_PK.parse()?;
+        let desc_pk: DescriptorPublicKey = TEST_KEY_TR.parse()?;
         let assets = Assets::new().add(desc_pk);
         let plan = def_desc.plan(&assets).expect("failed to create plan");
 
@@ -674,8 +673,7 @@ mod tests {
         // `assets`, forcing planning to use the script-path leaf (which sets
         // `plan.relative_timelock`).
         let secp = Secp256k1::new();
-        let desc_str =
-            format!("tr({TEST_HEX_PK},and_v(v:pk({TEST_DESCRIPTOR_PK}),older({csv_blocks})))");
+        let desc_str = format!("tr({TEST_KEY_HEX},and_v(v:pk({TEST_KEY_TR}),older({csv_blocks})))");
         let desc = Descriptor::parse_descriptor(&secp, &desc_str)?
             .0
             .at_derivation_index(0)?;
@@ -689,7 +687,7 @@ mod tests {
             }],
         };
         let assets = Assets::new()
-            .add(TEST_DESCRIPTOR_PK.parse::<DescriptorPublicKey>()?)
+            .add(TEST_KEY_TR.parse::<DescriptorPublicKey>()?)
             .older(relative::LockTime::from_height(csv_blocks));
         let plan = desc.plan(&assets).expect("script-path plan with CSV");
         let status = crate::ConfirmationStatus {