Speed up unit tests by only generating big fixtures once up front

services/track-changes/test/unit/coffee/UpdateCompressor/UpdateCompressorTests.coffee

@@ -5,14 +5,15 @@ expect = chai.expect
 modulePath = "../../../../app/js/UpdateCompressor.js"
 SandboxedModule = require('sandboxed-module')
 
+bigstring = ("a" for [0 .. 2*1024*1024]).join("")
+mediumstring = ("a" for [0 .. 1024*1024]).join("")
+
 describe "UpdateCompressor", ->
 	beforeEach ->
 		@UpdateCompressor = SandboxedModule.require modulePath, requires:
 			"../lib/diff_match_patch": require("../../../../app/lib/diff_match_patch")
 		@user_id = "user-id-1"
 		@other_user_id = "user-id-2"
-		@bigstring = ("a" for [0 .. 2*1024*1024]).join("")
-		@mediumstring = ("a" for [0 .. 1024*1024]).join("")
 		@ts1 = Date.now()
 		@ts2 = Date.now() + 1000
 
@@ -150,7 +151,7 @@ describe "UpdateCompressor", ->
 					meta: ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 6, i: @bigstring }
+					op: { p: 6, i: bigstring }
 					meta: ts: @ts2, user_id: @user_id
 					v: 43
 				}])
@@ -159,47 +160,47 @@ describe "UpdateCompressor", ->
 					meta: start_ts: @ts1, end_ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 6, i: @bigstring }
+					op: { p: 6, i: bigstring }
 					meta: start_ts: @ts2, end_ts: @ts2, user_id: @user_id
 					v: 43
 				}]
 
 			it "should not append inserts that are too big (first op)", ->
 				expect(@UpdateCompressor.compressUpdates [{
-					op: { p: 3, i: @bigstring }
+					op: { p: 3, i: bigstring }
 					meta: ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 3 + @bigstring.length, i: "bar" }
+					op: { p: 3 + bigstring.length, i: "bar" }
 					meta: ts: @ts2, user_id: @user_id
 					v: 43
 				}])
 				.to.deep.equal [{
-					op: { p: 3, i: @bigstring }
+					op: { p: 3, i: bigstring }
 					meta: start_ts: @ts1, end_ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 3 + @bigstring.length, i: "bar" }
+					op: { p: 3 + bigstring.length, i: "bar" }
 					meta: start_ts: @ts2, end_ts: @ts2, user_id: @user_id
 					v: 43
 				}]
 
 			it "should not append inserts that are too big (first and second op)", ->
 				expect(@UpdateCompressor.compressUpdates [{
-					op: { p: 3, i: @mediumstring }
+					op: { p: 3, i: mediumstring }
 					meta: ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 3 + @mediumstring.length, i: @mediumstring }
+					op: { p: 3 + mediumstring.length, i: mediumstring }
 					meta: ts: @ts2, user_id: @user_id
 					v: 43
 				}])
 				.to.deep.equal [{
-					op: { p: 3, i: @mediumstring }
+					op: { p: 3, i: mediumstring }
 					meta: start_ts: @ts1, end_ts: @ts1, user_id: @user_id
 					v: 42
 				}, {
-					op: { p: 3 + @mediumstring.length, i: @mediumstring }
+					op: { p: 3 + mediumstring.length, i: mediumstring }
 					meta: start_ts: @ts2, end_ts: @ts2, user_id: @user_id
 					v: 43
 				}]