feat: add pallets/consts endpoint (#1210)

* add endpoint for pallet constants
add unit and e2e tests

* update docs for consts endpoint

* merged master
added statemint consts e2e tests

* update abstractpalletservice

* add newline in response mocks

* yarn lint

* update docs

docs/src/openapi-v1.yaml

@@ -1052,6 +1052,113 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/Error'
+  /pallets/{palletId}/consts:
+    get:
+      tags:
+      - pallets
+      summary: Get a list of constants for a pallet.
+      description: Returns a list of const item metadata for constant items of the
+        specified palletId.
+      parameters:
+      - name: palletId
+        in: path
+        description: 'Name or index of the pallet to read constant metadata for. Note: the pallet name must match what is
+          specified in the runtime metadata.'
+        required: true
+        schema:
+          type: string
+      - name: onlyIds
+        in: query
+        description: Only return the names (IDs) of the const items instead of every constant's metadata.
+        required: false
+        schema:
+          type: boolean
+      - name: at
+        in: query
+        description: Block at which to retrieve a list of
+          the pallet's constant items.
+        required: false
+        schema:
+          type: string
+          description: Block identifier, as the block height or block hash.
+          format: unsignedInteger or $hex
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                type: array
+                description: Pallet info and Array of constantItemIds.
+                items:
+                  $ref: '#/components/schemas/PalletConstants'
+        "400":
+          description: invalid blockId supplied for at query param
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+        "404":
+          description: could not find pallet with palletId
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+  /pallets/{palletId}/consts/{constantItemId}:
+    get:
+      tags:
+      - pallets
+      summary: Get the value of a constant item.
+      description: Returns the value stored under the constantItemId.
+      parameters:
+      - name: palletId
+        in: path
+        description: 'Name or index of the pallet to read constant metadata for. Note: the pallet name must match what is
+          specified in the runtime metadata.'
+        required: true
+        schema:
+          type: string
+      - name: constantItemId
+        in: path
+        description: Id of the const item to query for.
+        required: true
+        schema:
+          type: string
+      - name: at
+        in: query
+        description: Block at which to query the const item at.
+        required: false
+        schema:
+          type: string
+          description: Block identifier, as the block height or block hash.
+          format: unsignedInteger or $hex
+      - name: metadata
+        in: query
+        description: Include the const items metadata (including documentation)
+          if set to true.
+        required: false
+        schema:
+          default: false
+          type: boolean
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/PalletConstantsItem'
+        "400":
+          description: invalid blockId supplied for at query param
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+        "404":
+          description: could not find resource with with id
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
   /pallets/{palletId}/errors:
     get:
       tags:
@@ -2650,6 +2757,59 @@ components:
           $ref: '#/components/schemas/AssetInfo'
         assetMetadata:
           $ref: '#/components/schemas/AssetMetadata'
+    PalletConstants:
+      type: object
+      properties:
+        at:
+          $ref: '#/components/schemas/BlockIdentifiers'
+        pallet:
+          type: string
+          description: Name of the pallet.
+          example: "democracy"
+        palletIndex:
+          type: string
+          description: Index of the pallet for looking up constants.
+          example: "14"
+        items:
+          type: array
+          items:
+            $ref: '#/components/schemas/PalletConstantsItemMetadata'
+          description: Array containing metadata for each constant entry of the pallet.
+    PalletConstantsItem:
+      type: object
+      properties:
+        pallet:
+          type: string
+          description: Name of the pallet.
+          example: "democracy"
+        palletIndex:
+          type: string
+          description: Index of the pallet for looking up constants.
+          example: "14"
+        errorItem:
+          type: string
+          description: Name of the constant item.
+          example: "EnactmentPeriod"
+        metadata:
+          $ref: '#/components/schemas/PalletConstantsItemMetadata'
+    PalletConstantsItemMetadata:
+      type: object
+      properties:
+        name:
+          type: string
+          example: "VotingPeriod"
+          description: The constant item's name (which is the same as the constant item's ID).
+        type:
+          type: string
+          example: "4"
+        value:
+         type: string
+         example: "0x00270600"
+         description: The hex value of the constant
+        docs:
+          type: string
+          example: "Information concerning any given constant.\n\n TWOX-NOTE: SAFE as indexes are not under an attacker’s control."
+      description: Metadata of an constant item from a FRAME pallet.
     PalletErrors:
       type: object
       properties:

e2e-tests/latest/endpoints/polkadot.ts

@@ -141,6 +141,18 @@ export const polkadot: IConfig = {
 		path: '/paras/head/backed-candidates',
 		queryParams: ['at={blockId}'],
 	},
+	'/pallets/{palletId}/consts': {
+		path: '/pallets/democracy/consts',
+		queryParams: ['at={blockId}'],
+	},
+	'/pallets/{palletId}/consts?onlyIds=true': {
+		path: '/pallets/14/consts',
+		queryParams: ['at={blockId}'],
+	},
+	'/pallets/{palletId}/consts/{constItemId}': {
+		path: '/pallets/democracy/consts/EnactmentPeriod',
+		queryParams: ['at={blockId}'],
+	},
 	'/pallets/{palletId}/errors': {
 		path: '/pallets/balances/errors',
 		queryParams: ['at={blockId}'],

e2e-tests/latest/endpoints/statemint.ts

@@ -27,6 +27,14 @@ export const statemint = {
 		path: '/pallets/assets/123/asset-info',
 		queryParams: ['at={blockId}'],
 	},
+	'/pallets/{palletId}/consts': {
+		path: '/pallets/assets/consts',
+		queryParams: ['at={blockId}'],
+	},
+	'/pallets/{palletId}/consts/{constantItemId}': {
+		path: '/pallets/assets/consts/AssetDeposit',
+		queryParams: ['at={blockId}'],
+	},
 	'/pallets/{palletId}/errors': {
 		path: '/pallets/assets/errors',
 		queryParams: ['at={blockId}'],

src/chains-config/defaultControllers.ts

@@ -36,6 +36,7 @@ export const defaultControllers: ControllerConfig = {
 		'NodeTransactionPool',
 		'NodeVersion',
 		'PalletsAssets',
+		'PalletsConsts',
 		'PalletsErrors',
 		'PalletsEvents',
 		'PalletsStakingProgress',

src/chains-config/kusamaControllers.ts

@@ -34,6 +34,7 @@ export const kusamaControllers: ControllerConfig = {
 		'NodeNetwork',
 		'NodeTransactionPool',
 		'NodeVersion',
+		'PalletsConsts',
 		'PalletsErrors',
 		'PalletsEvents',
 		'PalletsNominationPools',

src/chains-config/polkadotControllers.ts

@@ -34,6 +34,7 @@ export const polkadotControllers: ControllerConfig = {
 		'NodeNetwork',
 		'NodeTransactionPool',
 		'NodeVersion',
+		'PalletsConsts',
 		'PalletsErrors',
 		'PalletsEvents',
 		'PalletsNominationPools',

src/chains-config/statemineControllers.ts

@@ -31,6 +31,7 @@ export const statemineControllers: ControllerConfig = {
 		'NodeTransactionPool',
 		'NodeVersion',
 		'PalletsAssets',
+		'PalletsConsts',
 		'PalletsErrors',
 		'PalletsEvents',
 		'RuntimeCode',

src/chains-config/statemintControllers.ts

@@ -31,6 +31,7 @@ export const statemintControllers: ControllerConfig = {
 		'NodeTransactionPool',
 		'NodeVersion',
 		'PalletsAssets',
+		'PalletsConsts',
 		'PalletsEvents',
 		'PalletsErrors',
 		'RuntimeCode',

src/chains-config/westendControllers.ts

@@ -33,6 +33,7 @@ export const westendControllers: ControllerConfig = {
 		'NodeNetwork',
 		'NodeTransactionPool',
 		'NodeVersion',
+		'PalletsConsts',
 		'PalletsErrors',
 		'PalletsEvents',
 		'PalletsNominationPools',

src/controllers/index.ts

@@ -28,6 +28,7 @@ import { ContractsInk } from './contracts';
 import { NodeNetwork, NodeTransactionPool, NodeVersion } from './node';
 import {
 	PalletsAssets,
+	PalletsConsts,
 	PalletsErrors,
 	PalletsEvents,
 	PalletsNominationPools,
@@ -60,6 +61,7 @@ export const controllers = {
 	AccountsStakingPayouts,
 	ContractsInk,
 	PalletsAssets,
+	PalletsConsts,
 	PalletsErrors,
 	PalletsEvents,
 	PalletsNominationPools,

src/controllers/pallets/PalletsConstsController.ts

@@ -0,0 +1,91 @@
+// Copyright 2017-2022 Parity Technologies (UK) Ltd.
+// This file is part of Substrate API Sidecar.
+//
+// Substrate API Sidecar is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import { ApiPromise } from '@polkadot/api';
+import { stringCamelCase } from '@polkadot/util';
+import { RequestHandler } from 'express-serve-static-core';
+
+import { PalletsConstantsService } from '../../services';
+import { IPalletsConstantsParam } from '../../types/requests';
+import AbstractController from '../AbstractController';
+
+/**
+ * `/pallets/{palletId}/consts`
+ *
+ * Returns the metadata for each constant item of the pallet.
+ *
+ * `/pallets/{palletId}/consts/{constantItemId}`
+ *
+ * Returns the info for the constantItemId.
+ *
+ * See `docs/src/openapi-v1.yaml` for usage information.
+ */
+export default class PalletsConstantsController extends AbstractController<PalletsConstantsService> {
+	constructor(api: ApiPromise) {
+		super(api, '/pallets/:palletId/consts', new PalletsConstantsService(api));
+
+		this.initRoutes();
+	}
+
+	protected initRoutes(): void {
+		this.safeMountAsyncGetHandlers([
+			['/:constantItemId', this.getConstById as RequestHandler],
+			['/', this.getConsts],
+		]);
+	}
+
+	private getConstById: RequestHandler<
+		IPalletsConstantsParam,
+		unknown,
+		unknown
+	> = async (
+		{ query: { at, metadata }, params: { palletId, constantItemId } },
+		res
+	): Promise<void> => {
+		const metadataArg = metadata === 'true';
+		const hash = await this.getHashFromAt(at);
+		const historicApi = await this.api.at(hash);
+
+		PalletsConstantsController.sanitizedSend(
+			res,
+			await this.service.fetchConstantItem(historicApi, {
+				hash,
+				// stringCamelCase ensures we don't have snake case or kebab case
+				palletId: stringCamelCase(palletId),
+				constantItemId: stringCamelCase(constantItemId),
+				metadata: metadataArg,
+			})
+		);
+	};
+
+	private getConsts: RequestHandler = async (
+		{ params: { palletId }, query: { at, onlyIds } },
+		res
+	): Promise<void> => {
+		const onlyIdsArg = onlyIds === 'true';
+		const hash = await this.getHashFromAt(at);
+		const historicApi = await this.api.at(hash);
+
+		PalletsConstantsController.sanitizedSend(
+			res,
+			await this.service.fetchConstants(historicApi, {
+				hash,
+				palletId: stringCamelCase(palletId),
+				onlyIds: onlyIdsArg,
+			})
+		);
+	};
+}

src/controllers/pallets/index.ts

@@ -15,6 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 export { default as PalletsAssets } from './PalletsAssetsController';
+export { default as PalletsConsts } from './PalletsConstsController';
 export { default as PalletsErrors } from './PalletsErrorsController';
 export { default as PalletsEvents } from './PalletsEventsController';
 export { default as PalletsNominationPools } from './PalletsNominationPoolsController';