Define Reaction edges (#845)

This adds support to `github/edges` for creating edges representing
GitHub reactions. These edges are not actually added to the graph.

Test plan: Unit tests

src/plugins/github/__snapshots__/edges.test.js.snap

@@ -155,6 +155,127 @@ Object {
 }
 `;
 
+exports[`plugins/github/edges createEdge works for "reactsHeart" 1`] = `
+Object {
+  "addressParts": Array [
+    "sourcecred",
+    "github",
+    "REACTS",
+    "HEART",
+    "5",
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+    "6",
+    "sourcecred",
+    "github",
+    "PULL",
+    "sourcecred",
+    "example-github",
+    "5",
+  ],
+  "dstParts": Array [
+    "sourcecred",
+    "github",
+    "PULL",
+    "sourcecred",
+    "example-github",
+    "5",
+  ],
+  "srcParts": Array [
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+  ],
+}
+`;
+
+exports[`plugins/github/edges createEdge works for "reactsHooray" 1`] = `
+Object {
+  "addressParts": Array [
+    "sourcecred",
+    "github",
+    "REACTS",
+    "HOORAY",
+    "5",
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+    "8",
+    "sourcecred",
+    "github",
+    "COMMENT",
+    "ISSUE",
+    "sourcecred",
+    "example-github",
+    "2",
+    "373768703",
+  ],
+  "dstParts": Array [
+    "sourcecred",
+    "github",
+    "COMMENT",
+    "ISSUE",
+    "sourcecred",
+    "example-github",
+    "2",
+    "373768703",
+  ],
+  "srcParts": Array [
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+  ],
+}
+`;
+
+exports[`plugins/github/edges createEdge works for "reactsThumbsUp" 1`] = `
+Object {
+  "addressParts": Array [
+    "sourcecred",
+    "github",
+    "REACTS",
+    "THUMBS_UP",
+    "5",
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+    "6",
+    "sourcecred",
+    "github",
+    "ISSUE",
+    "sourcecred",
+    "example-github",
+    "2",
+  ],
+  "dstParts": Array [
+    "sourcecred",
+    "github",
+    "ISSUE",
+    "sourcecred",
+    "example-github",
+    "2",
+  ],
+  "srcParts": Array [
+    "sourcecred",
+    "github",
+    "USERLIKE",
+    "USER",
+    "decentralion",
+  ],
+}
+`;
+
 exports[`plugins/github/edges createEdge works for "references" 1`] = `
 Object {
   "addressParts": Array [

src/plugins/github/edges.js

@@ -9,6 +9,8 @@ import {
 import * as GithubNode from "./nodes";
 import * as GitNode from "../git/nodes";
 import type {MentionsAuthorReference} from "./heuristics/mentionsAuthorReference";
+// TODO(@decentralion): Opportunity to reduce bundle size (tree shaking?)
+import {Reactions, type ReactionContent} from "./graphql";
 
 export opaque type RawAddress: EdgeAddressT = EdgeAddressT;
 
@@ -17,6 +19,7 @@ export const MERGED_AS_TYPE = "MERGED_AS";
 export const HAS_PARENT_TYPE = "HAS_PARENT";
 export const REFERENCES_TYPE = "REFERENCES";
 export const MENTIONS_AUTHOR_TYPE = "MENTIONS_AUTHOR";
+export const REACTS_TYPE = "REACTS";
 
 const GITHUB_PREFIX = EdgeAddress.fromParts(["sourcecred", "github"]);
 function githubEdgeAddress(...parts: string[]): RawAddress {
@@ -30,6 +33,10 @@ export const Prefix = Object.freeze({
   references: githubEdgeAddress(REFERENCES_TYPE),
   hasParent: githubEdgeAddress(HAS_PARENT_TYPE),
   mentionsAuthor: githubEdgeAddress(MENTIONS_AUTHOR_TYPE),
+  reacts: githubEdgeAddress(REACTS_TYPE),
+  reactsThumbsUp: githubEdgeAddress(REACTS_TYPE, Reactions.THUMBS_UP),
+  reactsHeart: githubEdgeAddress(REACTS_TYPE, Reactions.HEART),
+  reactsHooray: githubEdgeAddress(REACTS_TYPE, Reactions.HOORAY),
 });
 
 export type AuthorsAddress = {|
@@ -54,13 +61,20 @@ export type MentionsAuthorAddress = {|
   +type: typeof MENTIONS_AUTHOR_TYPE,
   +reference: MentionsAuthorReference,
 |};
+export type ReactsAddress = {|
+  +type: typeof REACTS_TYPE,
+  +reactionType: ReactionContent,
+  +user: GithubNode.UserlikeAddress,
+  +reactable: GithubNode.ReactableAddress,
+|};
 
 export type StructuredAddress =
   | AuthorsAddress
   | MergedAsAddress
   | HasParentAddress
   | ReferencesAddress
-  | MentionsAuthorAddress;
+  | MentionsAuthorAddress
+  | ReactsAddress;
 
 export const createEdge = Object.freeze({
   authors: (
@@ -100,6 +114,20 @@ export const createEdge = Object.freeze({
     src: GithubNode.toRaw(reference.src),
     dst: GithubNode.toRaw(reference.dst),
   }),
+  reacts: (
+    reactionType: ReactionContent,
+    user: GithubNode.UserlikeAddress,
+    reactable: GithubNode.ReactableAddress
+  ): Edge => ({
+    address: toRaw({
+      type: REACTS_TYPE,
+      user,
+      reactionType,
+      reactable,
+    }),
+    src: GithubNode.toRaw(user),
+    dst: GithubNode.toRaw(reactable),
+  }),
 });
 
 function lengthEncode(x: GithubNode.RawAddress): $ReadOnlyArray<string> {
@@ -213,6 +241,25 @@ export function fromRaw(x: RawAddress): StructuredAddress {
       const reference = {src, dst, who};
       return {type: MENTIONS_AUTHOR_TYPE, reference};
     }
+    case REACTS_TYPE: {
+      const [rawReactionType, ...rest2] = rest;
+      const reactionType = Reactions[rawReactionType];
+      if (reactionType == null) {
+        throw fail();
+      }
+      const parts = multiLengthDecode(rest2, fail);
+      if (parts.length !== 2) {
+        throw fail();
+      }
+      const [userParts, reactableParts] = parts;
+      const user: GithubNode.UserlikeAddress = (GithubNode.fromRaw(
+        (NodeAddress.fromParts(userParts): any)
+      ): any);
+      const reactable: GithubNode.ReactableAddress = (GithubNode.fromRaw(
+        (NodeAddress.fromParts(reactableParts): any)
+      ): any);
+      return {type: REACTS_TYPE, reactionType, user, reactable};
+    }
     default:
       throw fail();
   }
@@ -249,6 +296,13 @@ export function toRaw(x: StructuredAddress): RawAddress {
         ...lengthEncode(GithubNode.toRaw(x.reference.dst)),
         ...lengthEncode(GithubNode.toRaw(x.reference.who))
       );
+    case REACTS_TYPE:
+      return EdgeAddress.append(
+        Prefix.reacts,
+        x.reactionType,
+        ...lengthEncode(GithubNode.toRaw(x.user)),
+        ...lengthEncode(GithubNode.toRaw(x.reactable))
+      );
     default:
       throw new Error((x.type: empty));
   }

src/plugins/github/edges.test.js

@@ -5,6 +5,7 @@ import {createEdge, fromRaw, toRaw} from "./edges";
 import * as GE from "./edges";
 import * as GN from "./nodes";
 import {COMMIT_TYPE} from "../git/nodes";
+import {Reactions} from "./graphql";
 
 describe("plugins/github/edges", () => {
   const nodeExamples = {
@@ -63,6 +64,24 @@ describe("plugins/github/edges", () => {
         dst: nodeExamples.issue(),
         who: nodeExamples.user(),
       }),
+    reactsHeart: () =>
+      createEdge.reacts(
+        Reactions.HEART,
+        nodeExamples.user(),
+        nodeExamples.pull()
+      ),
+    reactsThumbsUp: () =>
+      createEdge.reacts(
+        Reactions.THUMBS_UP,
+        nodeExamples.user(),
+        nodeExamples.issue()
+      ),
+    reactsHooray: () =>
+      createEdge.reacts(
+        Reactions.HOORAY,
+        nodeExamples.user(),
+        nodeExamples.issueComment()
+      ),
   };
 
   describe("createEdge", () => {

src/plugins/github/nodes.js

@@ -120,6 +120,9 @@ export type ParentAddress =
   | PullAddress
   | ReviewAddress;
 
+// GitHub allows you to react to these types
+export type ReactableAddress = IssueAddress | PullAddress | CommentAddress;
+
 // Each of these types may have Comments as children
 export type CommentableAddress = IssueAddress | PullAddress | ReviewAddress;