templates: add toJSON for clearer error message

src/templates/multisig/input.js

@@ -19,6 +19,7 @@ function check (script, allowIncomplete) {
 
   return chunks.slice(1).every(bscript.isCanonicalSignature)
 }
+check.toJSON = function () { return 'multi-sig input' }
 
 function encode (signatures, scriptPubKey) {
   typeforce([partialSignature], signatures)

src/templates/multisig/output.js

@@ -25,6 +25,7 @@ function check (script, allowIncomplete) {
   var keys = chunks.slice(1, -2)
   return keys.every(bscript.isCanonicalPubKey)
 }
+check.toJSON = function () { return 'multi-sig output' }
 
 function encode (m, pubKeys) {
   typeforce({

src/templates/nulldata.js

@@ -11,6 +11,7 @@ function check (script) {
   return buffer.length > 1 &&
     buffer[0] === OPS.OP_RETURN
 }
+check.toJSON = function () { return 'null data output' }
 
 function encode (data) {
   typeforce(types.Buffer, data)

src/templates/pubkey/input.js

@@ -10,6 +10,7 @@ function check (script) {
   return chunks.length === 1 &&
     bscript.isCanonicalSignature(chunks[0])
 }
+check.toJSON = function () { return 'pubKey input' }
 
 function encode (signature) {
   typeforce(types.Buffer, signature)

src/templates/pubkey/output.js

@@ -11,6 +11,7 @@ function check (script) {
     bscript.isCanonicalPubKey(chunks[0]) &&
     chunks[1] === OPS.OP_CHECKSIG
 }
+check.toJSON = function () { return 'pubKey output' }
 
 function encode (pubKey) {
   typeforce(bscript.isCanonicalPubKey, pubKey)

src/templates/pubkeyhash/input.js

@@ -11,6 +11,7 @@ function check (script) {
     bscript.isCanonicalSignature(chunks[0]) &&
     bscript.isCanonicalPubKey(chunks[1])
 }
+check.toJSON = function () { return 'pubKeyHash input' }
 
 function encode (signature, pubKey) {
   typeforce({

src/templates/pubkeyhash/output.js

@@ -15,6 +15,7 @@ function check (script) {
     buffer[23] === OPS.OP_EQUALVERIFY &&
     buffer[24] === OPS.OP_CHECKSIG
 }
+check.toJSON = function () { return 'pubKeyHash output' }
 
 function encode (pubKeyHash) {
   typeforce(types.Hash160bit, pubKeyHash)

src/templates/scripthash/input.js

@@ -20,6 +20,7 @@ function check (script, allowIncomplete) {
   var outputType = bscript.classifyOutput(redeemScriptChunks)
   return inputType === outputType
 }
+check.toJSON = function () { return 'scriptHash input' }
 
 function encode (scriptSignature, scriptPubKey) {
   var scriptSigChunks = bscript.decompile(scriptSignature)

src/templates/scripthash/output.js

@@ -13,6 +13,7 @@ function check (script) {
     buffer[1] === 0x14 &&
     buffer[22] === OPS.OP_EQUAL
 }
+check.toJSON = function () { return 'scriptHash output' }
 
 function encode (scriptHash) {
   typeforce(types.Hash160bit, scriptHash)

src/templates/witnesspubkeyhash/output.js

@@ -12,6 +12,7 @@ function check (script) {
     buffer[0] === OPS.OP_0 &&
     buffer[1] === 0x14
 }
+check.toJSON = function () { return 'Witness pubKeyHash output' }
 
 function encode (pubKeyHash) {
   typeforce(types.Hash160bit, pubKeyHash)

src/templates/witnessscripthash/output.js

@@ -12,6 +12,7 @@ function check (script) {
     buffer[0] === OPS.OP_0 &&
     buffer[1] === 0x20
 }
+check.toJSON = function () { return 'Witness scriptHash output' }
 
 function encode (scriptHash) {
   typeforce(types.Hash256bit, scriptHash)

test/templates.js

@@ -323,17 +323,22 @@ describe('script-templates', function () {
     })
   })
 
-  describe('witnessScriptHash.outputs.encode', function () {
+  describe('witnessScriptHash.output', function () {
     fixtures.valid.forEach(function (f) {
       if (f.type !== 'witnessscripthash') return
       if (!f.scriptPubKey) return
 
-      it('returns ' + f.scriptPubKey, function () {
-        var witnessScriptPubKey = bscript.fromASM(f.witnessScriptPubKey)
-        var scriptPubKey = bscript.witnessScriptHash.output.encode(bcrypto.hash256(witnessScriptPubKey))
+      var witnessScriptPubKey = bscript.fromASM(f.witnessScriptPubKey)
+      var scriptHash = bcrypto.hash256(witnessScriptPubKey)
+      var scriptPubKey = bscript.witnessScriptHash.output.encode(scriptHash)
 
+      it('encodes to ' + f.scriptPubKey, function () {
         assert.strictEqual(bscript.toASM(scriptPubKey), f.scriptPubKey)
       })
+
+      it('decodes to ' + scriptHash.toString('hex'), function () {
+        assert.deepEqual(bscript.witnessScriptHash.output.decode(scriptHash), witnessScriptPubKey)
+      })
     })
 
     fixtures.invalid.witnessScriptHash.outputs.forEach(function (f) {