Merge pull request #11 from ethereumjs/add-active-hardfork

Added activeHardfork() function

Author: holgerd77

docs/index.md

@@ -13,61 +13,62 @@
     -   [hardforkIsActiveOnBlock][9]
     -   [hardforkIsActiveOnChain][10]
     -   [activeHardforks][11]
-    -   [hardforkBlock][12]
-    -   [isHardforkBlock][13]
-    -   [consensus][14]
-    -   [finality][15]
-    -   [genesis][16]
-    -   [hardforks][17]
-    -   [bootstrapNodes][18]
-    -   [hardfork][19]
-    -   [chainId][20]
-    -   [chainName][21]
-    -   [networkId][22]
+    -   [activeHardfork][12]
+    -   [hardforkBlock][13]
+    -   [isHardforkBlock][14]
+    -   [consensus][15]
+    -   [finality][16]
+    -   [genesis][17]
+    -   [hardforks][18]
+    -   [bootstrapNodes][19]
+    -   [hardfork][20]
+    -   [chainId][21]
+    -   [chainName][22]
+    -   [networkId][23]
 
 ## Common
 
 Common class to access chain and hardfork parameters
 
 **Parameters**
 
--   `chain` **([String][23] \| [Number][24])** String ('mainnet') or Number (1) chain representation
--   `hardfork` **[String][23]** String identifier ('byzantium') for hardfork (optional)
--   `supportedHardforks` **[Array][25]** Limit parameter returns to the given hardforks (optional)
+-   `chain` **([String][24] \| [Number][25])** String ('mainnet') or Number (1) chain representation
+-   `hardfork` **[String][24]** String identifier ('byzantium') for hardfork (optional)
+-   `supportedHardforks` **[Array][26]** Limit parameter returns to the given hardforks (optional)
 
 ### setChain
 
 Sets the chain
 
 **Parameters**
 
--   `chain` **([String][23] \| [Number][24])** String ('mainnet') or Number (1) chain representation
+-   `chain` **([String][24] \| [Number][25])** String ('mainnet') or Number (1) chain representation
 
 ### setHardfork
 
 Sets the hardfork to get params for
 
 **Parameters**
 
--   `hardfork` **[String][23]** String identifier ('byzantium')
+-   `hardfork` **[String][24]** String identifier ('byzantium')
 
 ### \_chooseHardfork
 
 Internal helper function to choose between hardfork set and hardfork provided as param
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork given to function as a parameter
+-   `hardfork` **[String][24]** Hardfork given to function as a parameter
 
-Returns **[String][23]** Hardfork chosen to be used
+Returns **[String][24]** Hardfork chosen to be used
 
 ### \_getHardfork
 
 Internal helper function, returns the params for the given hardfork for the chain set
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name
+-   `hardfork` **[String][24]** Hardfork name
 
 Returns **Dictionary** 
 
@@ -77,107 +78,119 @@ Internal helper function to check if a hardfork is set to be supported by the li
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name
+-   `hardfork` **[String][24]** Hardfork name
 
-Returns **[Boolean][26]** True if hardfork is supported
+Returns **[Boolean][27]** True if hardfork is supported
 
 ### param
 
 Returns the parameter corresponding to a hardfork
 
 **Parameters**
 
--   `topic` **[String][23]** Parameter topic ('gasConfig', 'gasPrices', 'vm', 'pow', 'casper', 'sharding')
--   `name` **[String][23]** Parameter name (e.g. 'minGasLimit' for 'gasConfig' topic)
--   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
+-   `topic` **[String][24]** Parameter topic ('gasConfig', 'gasPrices', 'vm', 'pow', 'casper', 'sharding')
+-   `name` **[String][24]** Parameter name (e.g. 'minGasLimit' for 'gasConfig' topic)
+-   `hardfork` **[String][24]** Hardfork name, optional if hardfork set
 
 ### paramByBlock
 
 Returns a parameter for the hardfork active on block number
 
 **Parameters**
 
--   `topic` **[String][23]** Parameter topic
--   `name` **[String][23]** Parameter name
--   `blockNumber` **[Number][24]** Block number
+-   `topic` **[String][24]** Parameter topic
+-   `name` **[String][24]** Parameter name
+-   `blockNumber` **[Number][25]** Block number
 
 ### hardforkIsActiveOnBlock
 
 Checks if a hardfork is active for a given block number
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name
--   `blockNumber` **[Number][24]** 
--   `opts` **[Array][25]** 
+-   `hardfork` **[String][24]** Hardfork name
+-   `blockNumber` **[Number][25]** 
+-   `opts` **[Array][26]** 
     -   `opts.onlySupported` **Array.Boolean** optional, only allow supported HFs (default: false)
 
-Returns **[Boolean][26]** 
+Returns **[Boolean][27]** 
 
 ### hardforkIsActiveOnChain
 
 Checks if the hardfork provided is active on the chain
 
 **Parameters**
 
--   `hardfork` **[String][23]** 
--   `opts` **[Array][25]** 
+-   `hardfork` **[String][24]** 
+-   `opts` **[Array][26]** 
     -   `opts.onlySupported` **Array.Boolean** optional, only allow supported HFs (default: false)
 
-Returns **[Boolean][26]** 
+Returns **[Boolean][27]** 
 
 ### activeHardforks
 
 Returns the active hardfork switches for the current chain
 
 **Parameters**
 
--   `blockNumber` **[Number][24]** up to block if provided, otherwise for the whole chain
--   `opts` **[Array][25]** 
+-   `blockNumber` **[Number][25]** up to block if provided, otherwise for the whole chain
+-   `opts` **[Array][26]** 
     -   `opts.onlySupported` **Array.Boolean** optional, limit results to supported HFs (default: false)
 
-Returns **[Array][25]** Array with hardfork arrays
+Returns **[Array][26]** Array with hardfork arrays
+
+### activeHardfork
+
+Returns the latest active hardfork name for chain or block or throws if unavailable
+
+**Parameters**
+
+-   `blockNumber` **[Number][25]** up to block if provided, otherwise for the whole chain
+-   `opts` **[Array][26]** 
+    -   `opts.onlySupported` **Array.Boolean** optional, limit results to supported HFs (default: false)
+
+Returns **[String][24]** Hardfork name
 
 ### hardforkBlock
 
 Returns the hardfork change block for the given hardfork
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name
+-   `hardfork` **[String][24]** Hardfork name
 
-Returns **[Number][24]** Block number
+Returns **[Number][25]** Block number
 
 ### isHardforkBlock
 
 True if block number provided is the hardfork change block of the current chain
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name
--   `blockNumber` **[Number][24]** Number of the block to check
+-   `hardfork` **[String][24]** Hardfork name
+-   `blockNumber` **[Number][25]** Number of the block to check
 
-Returns **[Boolean][26]** 
+Returns **[Boolean][27]** 
 
 ### consensus
 
 Provide the consensus type for the hardfork set or provided as param
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
+-   `hardfork` **[String][24]** Hardfork name, optional if hardfork set
 
-Returns **[String][23]** Consensus type (e.g. 'pow', 'poa')
+Returns **[String][24]** Consensus type (e.g. 'pow', 'poa')
 
 ### finality
 
 Provide the finality type for the hardfork set or provided as param
 
 **Parameters**
 
--   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
+-   `hardfork` **[String][24]** Hardfork name, optional if hardfork set
 
-Returns **[String][23]** Finality type (e.g. 'pos', null of no finality)
+Returns **[String][24]** Finality type (e.g. 'pos', null of no finality)
 
 ### genesis
 
@@ -189,7 +202,7 @@ Returns **Dictionary** Genesis dict
 
 Returns the hardforks for current chain
 
-Returns **[Array][25]** Array with arrays of hardforks
+Returns **[Array][26]** Array with arrays of hardforks
 
 ### bootstrapNodes
 
@@ -201,25 +214,25 @@ Returns **Dictionary** Dict with bootstrap nodes
 
 Returns the hardfork set
 
-Returns **[String][23]** Hardfork name
+Returns **[String][24]** Hardfork name
 
 ### chainId
 
 Returns the Id of current chain
 
-Returns **[Number][24]** chain Id
+Returns **[Number][25]** chain Id
 
 ### chainName
 
 Returns the name of current chain
 
-Returns **[String][23]** chain name (lower case)
+Returns **[String][24]** chain name (lower case)
 
 ### networkId
 
 Returns the Id of current network
 
-Returns **[Number][24]** network Id
+Returns **[Number][25]** network Id
 
 [1]: #common
 
@@ -243,32 +256,34 @@ Returns **[Number][24]** network Id
 
 [11]: #activehardforks
 
-[12]: #hardforkblock
+[12]: #activehardfork
+
+[13]: #hardforkblock
 
-[13]: #ishardforkblock
+[14]: #ishardforkblock
 
-[14]: #consensus
+[15]: #consensus
 
-[15]: #finality
+[16]: #finality
 
-[16]: #genesis
+[17]: #genesis
 
-[17]: #hardforks
+[18]: #hardforks
 
-[18]: #bootstrapnodes
+[19]: #bootstrapnodes
 
-[19]: #hardfork
+[20]: #hardfork
 
-[20]: #chainid
+[21]: #chainid
 
-[21]: #chainname
+[22]: #chainname
 
-[22]: #networkid
+[23]: #networkid
 
-[23]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+[24]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
 
-[24]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+[25]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
 
-[25]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array
+[26]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array
 
-[26]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+[27]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean

index.js

@@ -203,6 +203,22 @@ class Common {
     return activeHardforks
   }
 
+  /**
+   * Returns the latest active hardfork name for chain or block or throws if unavailable
+   * @param {Number} blockNumber up to block if provided, otherwise for the whole chain
+   * @param {Array} opts
+   * @param {Array.Boolean} opts.onlySupported optional, limit results to supported HFs (default: false)
+   * @return {String} Hardfork name
+   */
+  activeHardfork (blockNumber, opts) {
+    let activeHardforks = this.activeHardforks(blockNumber, opts)
+    if (activeHardforks.length > 0) {
+      return activeHardforks[activeHardforks.length - 1]['name']
+    } else {
+      throw new Error(`No (supported) active hardfork found`)
+    }
+  }
+
   /**
    * Returns the hardfork change block for the given hardfork
    * @param {String} hardfork Hardfork name

tests/hardforks.js

@@ -51,6 +51,17 @@ tape('[Common]: Hardfork logic', function (t) {
     st.end()
   })
 
+  t.test('activeHardfork()', function (st) {
+    let c = new Common('ropsten')
+    st.equal(c.activeHardfork(), 'byzantium', 'should return byzantium as latest active HF for Ropsten')
+    st.equal(c.activeHardfork(10), 'spuriousDragon', 'should return spuriousDragon as latest active HF for Ropsten for block 10')
+
+    c = new Common('ropsten', null, ['tangerineWhistle', 'spuriousDragon'])
+    st.equal(c.activeHardfork(null, { onlySupported: true }), 'spuriousDragon', 'should return spuriousDragon as latest active HF for Ropsten with limited supported hardforks')
+
+    st.end()
+  })
+
   t.test('hardforkIsActiveOnChain()', function (st) {
     let c = new Common('ropsten')
     st.equal(c.hardforkIsActiveOnChain('byzantium'), true, 'should return true for byzantium on Ropsten')