diff --git a/.eslintrc.json b/.eslintrc.json
index 60f8a7ee5..d15f3868c 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -17,6 +17,7 @@
     "no-var": 2,
     "prefer-const": 2,
     "no-unused-vars": "off",
+    "import/export": "off",
     "@typescript-eslint/no-unused-vars": ["error", { "vars": "all", "args": "after-used", "ignoreRestSiblings": false }]
   }
 }
diff --git a/package.json b/package.json
index e86c7e550..c9bfde3d7 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
   "types": "dist/liquid.d.ts",
   "browser": "dist/liquid.js",
   "scripts": {
-    "lint": "eslint . --ext .ts --ext .js",
+    "lint": "eslint . --ext .ts",
     "unit": "mocha 'test/unit/**/*.ts'",
     "e2e": "npm run build && mocha 'test/e2e/**/*.ts'",
     "test": "npm run unit && npm run e2e",
@@ -62,7 +62,7 @@
     "eslint": "^5.12.1",
     "eslint-config-standard": "^12.0.0",
     "eslint-plugin-import": "^2.15.0",
-    "eslint-plugin-mocha": "^5.2.1",
+    "eslint-plugin-mocha": "^5.3.0",
     "eslint-plugin-node": "^8.0.1",
     "eslint-plugin-promise": "^4.0.1",
     "eslint-plugin-standard": "^4.0.0",
diff --git a/src/builtin/filters/string.ts b/src/builtin/filters/string.ts
index d929af196..b7a3467e8 100644
--- a/src/builtin/filters/string.ts
+++ b/src/builtin/filters/string.ts
@@ -1,4 +1,4 @@
-import FilterImpl from "src/template/filter/filter-impl";
+import { FilterImpl } from 'src/template/filter/filter-impl'
 
 export default {
   'append': (v: string, arg: string) => v + arg,
diff --git a/src/builtin/filters/url.ts b/src/builtin/filters/url.ts
index f43025062..d3f5024a1 100644
--- a/src/builtin/filters/url.ts
+++ b/src/builtin/filters/url.ts
@@ -1,4 +1,4 @@
 export default {
   'url_decode': (x: string) => x.split('+').map(decodeURIComponent).join(' '),
   'url_encode': (x: string) => x.split(' ').map(encodeURIComponent).join('+')
-}
\ No newline at end of file
+}
diff --git a/src/builtin/tags/assign.ts b/src/builtin/tags/assign.ts
index c8edfbc6b..e6849be6a 100644
--- a/src/builtin/tags/assign.ts
+++ b/src/builtin/tags/assign.ts
@@ -1,9 +1,9 @@
 import assert from 'src/util/assert'
 import { identifier } from 'src/parser/lexical'
 import { AssignScope } from 'src/scope/scopes'
-import TagToken from 'src/parser/tag-token';
-import Scope from 'src/scope/scope';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import TagToken from 'src/parser/tag-token'
+import Scope from 'src/scope/scope'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 const re = new RegExp(`(${identifier.source})\\s*=([^]*)`)
 
@@ -20,4 +20,4 @@ export default {
     scope.push(ctx)
     return Promise.resolve('')
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/block.ts b/src/builtin/tags/block.ts
index a5b83c7eb..93f8f98f3 100644
--- a/src/builtin/tags/block.ts
+++ b/src/builtin/tags/block.ts
@@ -1,10 +1,10 @@
 import BlockMode from 'src/scope/block-mode'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
 import ITemplate from 'src/template/itemplate'
-import Scope from 'src/scope/scope';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import Scope from 'src/scope/scope'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 export default {
   parse: function (token: TagToken, remainTokens: Token[]) {
diff --git a/src/builtin/tags/capture.ts b/src/builtin/tags/capture.ts
index dad1bec47..b2e3bef82 100644
--- a/src/builtin/tags/capture.ts
+++ b/src/builtin/tags/capture.ts
@@ -4,7 +4,7 @@ import { CaptureScope } from 'src/scope/scopes'
 import TagToken from 'src/parser/tag-token'
 import Token from 'src/parser/token'
 import Scope from 'src/scope/scope'
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 const re = new RegExp(`(${identifier.source})`)
 
diff --git a/src/builtin/tags/case.ts b/src/builtin/tags/case.ts
index 18a7f654f..7b4f21177 100644
--- a/src/builtin/tags/case.ts
+++ b/src/builtin/tags/case.ts
@@ -1,10 +1,10 @@
 import { evalExp } from 'src/render/syntax'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import Scope from 'src/scope/scope';
-import ITemplate from 'src/template/itemplate';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import Scope from 'src/scope/scope'
+import ITemplate from 'src/template/itemplate'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: Token[]) {
@@ -41,4 +41,4 @@ export default {
     }
     return this.liquid.renderer.renderTemplates(this.elseTemplates, scope)
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/comment.ts b/src/builtin/tags/comment.ts
index 64612b58d..f23460fa3 100644
--- a/src/builtin/tags/comment.ts
+++ b/src/builtin/tags/comment.ts
@@ -1,6 +1,6 @@
-import TagToken from "src/parser/tag-token";
-import Token from "src/parser/token";
-import ITagImplOptions from "src/template/tag/itag-impl-options";
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: Token[]) {
@@ -14,4 +14,4 @@ export default {
       })
     stream.start()
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/cycle.ts b/src/builtin/tags/cycle.ts
index ef51c16e1..c9f5fb19f 100644
--- a/src/builtin/tags/cycle.ts
+++ b/src/builtin/tags/cycle.ts
@@ -1,9 +1,9 @@
 import assert from 'src/util/assert'
 import { value as rValue } from 'src/parser/lexical'
 import { evalValue } from 'src/render/syntax'
-import TagToken from 'src/parser/tag-token';
-import Scope from 'src/scope/scope';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import TagToken from 'src/parser/tag-token'
+import Scope from 'src/scope/scope'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 const groupRE = new RegExp(`^(?:(${rValue.source})\\s*:\\s*)?(.*)$`)
 const candidatesRE = new RegExp(rValue.source, 'g')
@@ -40,4 +40,4 @@ export default <ITagImplOptions>{
 
     return evalValue(candidate, scope)
   }
-}
\ No newline at end of file
+}
diff --git a/src/builtin/tags/decrement.ts b/src/builtin/tags/decrement.ts
index 6fa56b422..3c0dbea0f 100644
--- a/src/builtin/tags/decrement.ts
+++ b/src/builtin/tags/decrement.ts
@@ -3,7 +3,7 @@ import { identifier } from 'src/parser/lexical'
 import { CaptureScope, AssignScope, DecrementScope } from 'src/scope/scopes'
 import TagToken from 'src/parser/tag-token'
 import Scope from 'src/scope/scope'
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 export default {
   parse: function (token: TagToken) {
@@ -27,4 +27,4 @@ export default {
     }
     return --context[this.variable]
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/for.ts b/src/builtin/tags/for.ts
index 8b4429c6a..49b62d70f 100644
--- a/src/builtin/tags/for.ts
+++ b/src/builtin/tags/for.ts
@@ -3,13 +3,13 @@ import { isString, isObject, isArray } from 'src/util/underscore'
 import { evalExp } from 'src/render/syntax'
 import assert from 'src/util/assert'
 import { identifier, value, hash } from 'src/parser/lexical'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import Scope from 'src/scope/scope';
-import Hash from 'src/template/tag/hash';
-import ITemplate from 'src/template/itemplate';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import Scope from 'src/scope/scope'
+import Hash from 'src/template/tag/hash'
+import ITemplate from 'src/template/itemplate'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 const re = new RegExp(`^(${identifier.source})\\s+in\\s+` +
   `(${value.source})` +
@@ -25,10 +25,10 @@ export default <ITagImplOptions>{
     this.variable = match[1]
     this.collection = match[2]
     this.reversed = !!match[3]
-  
+
     this.templates = []
     this.elseTemplates = []
-  
+
     let p
     const stream: ParseStream = this.liquid.parser.parseStream(remainTokens)
       .on('start', () => (p = this.templates))
@@ -38,12 +38,12 @@ export default <ITagImplOptions>{
       .on('end', () => {
         throw new Error(`tag ${tagToken.raw} not closed`)
       })
-  
+
     stream.start()
   },
   render: async function (scope: Scope, hash: Hash) {
     let collection = evalExp(this.collection, scope)
-  
+
     if (!isArray(collection)) {
       if (isString(collection) && collection.length > 0) {
         collection = [collection] as string[]
@@ -54,13 +54,13 @@ export default <ITagImplOptions>{
     if (!isArray(collection) || !collection.length) {
       return this.liquid.renderer.renderTemplates(this.elseTemplates, scope)
     }
-  
+
     const offset = hash.offset || 0
     const limit = (hash.limit === undefined) ? collection.length : hash.limit
-  
+
     collection = collection.slice(offset, offset + limit)
     if (this.reversed) collection.reverse()
-  
+
     const contexts = collection.map((item: string, i: number) => {
       const ctx = {}
       ctx[this.variable] = item
@@ -75,12 +75,12 @@ export default <ITagImplOptions>{
       }
       return ctx
     })
-  
+
     let html = ''
     let finished = false
     await mapSeries(contexts, async context => {
       if (finished) return
-  
+
       scope.push(context)
       try {
         html += await this.liquid.renderer.renderTemplates(this.templates, scope)
@@ -96,4 +96,4 @@ export default <ITagImplOptions>{
     })
     return html
   }
-}
\ No newline at end of file
+}
diff --git a/src/builtin/tags/if.ts b/src/builtin/tags/if.ts
index eabce1ba6..7ef720af5 100644
--- a/src/builtin/tags/if.ts
+++ b/src/builtin/tags/if.ts
@@ -1,10 +1,10 @@
 import { evalExp, isTruthy } from 'src/render/syntax'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import Scope from 'src/scope/scope';
-import ITemplate from 'src/template/itemplate';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import Scope from 'src/scope/scope'
+import ITemplate from 'src/template/itemplate'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: Token[]) {
diff --git a/src/builtin/tags/include.ts b/src/builtin/tags/include.ts
index 3e2f0d6aa..58dfb446a 100644
--- a/src/builtin/tags/include.ts
+++ b/src/builtin/tags/include.ts
@@ -2,10 +2,10 @@ import assert from 'src/util/assert'
 import { value, quotedLine } from 'src/parser/lexical'
 import { evalValue } from 'src/render/syntax'
 import BlockMode from 'src/scope/block-mode'
-import TagToken from 'src/parser/tag-token';
-import Scope from 'src/scope/scope';
-import Hash from 'src/template/tag/hash';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import TagToken from 'src/parser/tag-token'
+import Scope from 'src/scope/scope'
+import Hash from 'src/template/tag/hash'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 const staticFileRE = /[^\s,]+/
 const withRE = new RegExp(`with\\s+(${value.source})`)
diff --git a/src/builtin/tags/increment.ts b/src/builtin/tags/increment.ts
index c5d91e306..ef3e9f260 100644
--- a/src/builtin/tags/increment.ts
+++ b/src/builtin/tags/increment.ts
@@ -1,7 +1,7 @@
 import assert from 'src/util/assert'
 import { identifier } from 'src/parser/lexical'
 import { CaptureScope, AssignScope, IncrementScope } from 'src/scope/scopes'
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 export default {
   parse: function (token) {
@@ -27,4 +27,4 @@ export default {
     context[this.variable]++
     return val
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/layout.ts b/src/builtin/tags/layout.ts
index f6ccb9f62..ad87ff8c9 100644
--- a/src/builtin/tags/layout.ts
+++ b/src/builtin/tags/layout.ts
@@ -2,11 +2,11 @@ import assert from 'src/util/assert'
 import { value as rValue } from 'src/parser/lexical'
 import { evalValue } from 'src/render/syntax'
 import BlockMode from 'src/scope/block-mode'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import Scope from 'src/scope/scope';
-import Hash from 'src/template/tag/hash';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import Scope from 'src/scope/scope'
+import Hash from 'src/template/tag/hash'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 const staticFileRE = /\S+/
 
diff --git a/src/builtin/tags/raw.ts b/src/builtin/tags/raw.ts
index 8c6579d29..0bd10978e 100644
--- a/src/builtin/tags/raw.ts
+++ b/src/builtin/tags/raw.ts
@@ -1,6 +1,6 @@
-import TagToken from "src/parser/tag-token";
-import Token from "src/parser/token";
-import ITagImplOptions from "src/template/tag/itag-impl-options";
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
 
 export default <ITagImplOptions>{
   parse: function (tagToken: TagToken, remainTokens: Token[]) {
diff --git a/src/builtin/tags/tablerow.ts b/src/builtin/tags/tablerow.ts
index 2494a07fc..d9d8906e4 100644
--- a/src/builtin/tags/tablerow.ts
+++ b/src/builtin/tags/tablerow.ts
@@ -2,13 +2,13 @@ import { mapSeries } from 'src/util/promise'
 import assert from 'src/util/assert'
 import { evalExp } from 'src/render/syntax'
 import { identifier, value, hash } from 'src/parser/lexical'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import ITemplate from 'src/template/itemplate';
-import Scope from 'src/scope/scope';
-import Hash from 'src/template/tag/hash';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import ITemplate from 'src/template/itemplate'
+import Scope from 'src/scope/scope'
+import Hash from 'src/template/tag/hash'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 const re = new RegExp(`^(${identifier.source})\\s+in\\s+` +
   `(${value.source})` +
@@ -72,4 +72,4 @@ export default {
     }
     return html
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/builtin/tags/unless.ts b/src/builtin/tags/unless.ts
index e50e158e6..577be8713 100644
--- a/src/builtin/tags/unless.ts
+++ b/src/builtin/tags/unless.ts
@@ -1,10 +1,9 @@
 import { evalExp, isFalsy } from 'src/render/syntax'
-import TagToken from 'src/parser/tag-token';
-import Token from 'src/parser/token';
-import ITemplate from 'src/template/itemplate';
-import Scope from 'src/scope/scope';
-import ITagImplOptions from 'src/template/tag/itag-impl-options';
-import ParseStream from 'src/parser/parse-stream';
+import TagToken from 'src/parser/tag-token'
+import Token from 'src/parser/token'
+import Scope from 'src/scope/scope'
+import ITagImplOptions from 'src/template/tag/itag-impl-options'
+import ParseStream from 'src/parser/parse-stream'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: Token[]) {
@@ -32,4 +31,4 @@ export default {
       ? this.liquid.renderer.renderTemplates(this.templates, scope)
       : this.liquid.renderer.renderTemplates(this.elseTemplates, scope)
   }
-} as ITagImplOptions
\ No newline at end of file
+} as ITagImplOptions
diff --git a/src/liquid.ts b/src/liquid.ts
index f70eb1493..121df8a75 100644
--- a/src/liquid.ts
+++ b/src/liquid.ts
@@ -14,7 +14,7 @@ import { isTruthy, isFalsy, evalExp, evalValue } from './render/syntax'
 import builtinTags from './builtin/tags'
 import builtinFilters from './builtin/filters'
 import { LiquidOptions, NormalizedFullOptions, applyDefault, normalize } from './liquid-options'
-import FilterImpl from './template/filter/filter-impl';
+import { FilterImpl } from './template/filter/filter-impl'
 
 export default class Liquid {
   public options: NormalizedFullOptions
diff --git a/src/parser/lexical.ts b/src/parser/lexical.ts
index c379bba36..ce710fefb 100644
--- a/src/parser/lexical.ts
+++ b/src/parser/lexical.ts
@@ -6,7 +6,7 @@ export const quoteBalanced = new RegExp(`(?:${quoted.source}|[^'"])*`)
 
 // basic types
 export const integer = /-?\d+/
-export const number = /-?\d+\.?\d*|\.?\d+/
+export const number = /[+-]?(?:\d+\.?\d*|\.?\d+)/
 export const bool = /true|false/
 
 // property access
diff --git a/src/parser/parse-stream.ts b/src/parser/parse-stream.ts
index da0fe61ba..92424efa9 100644
--- a/src/parser/parse-stream.ts
+++ b/src/parser/parse-stream.ts
@@ -1,6 +1,6 @@
 import Token from 'src/parser/token'
 import ITemplate from 'src/template/itemplate'
-import TagToken from './tag-token';
+import TagToken from './tag-token'
 
 type ParseToken = ((token: Token, remainTokens: Array<Token>) => ITemplate)
 
@@ -18,7 +18,7 @@ export default class ParseStream {
     this.handlers[name] = cb
     return this
   }
-  trigger <T extends Token | ITemplate>(event: string, arg?: T) {
+  trigger <T extends Token | ITemplate> (event: string, arg?: T) {
     const h = this.handlers[event]
     if (typeof h === 'function') {
       h(arg)
diff --git a/src/render/render.ts b/src/render/render.ts
index 6ea49ecc3..8c35d9dc6 100644
--- a/src/render/render.ts
+++ b/src/render/render.ts
@@ -1,7 +1,7 @@
-import { RenderBreakError, RenderError } from 'src/util/error'
+import { RenderError } from 'src/util/error'
 import assert from 'src/util/assert'
-import Scope from 'src/scope/scope';
-import ITemplate from 'src/template/itemplate';
+import Scope from 'src/scope/scope'
+import ITemplate from 'src/template/itemplate'
 
 export default class Render {
   async renderTemplates (templates: ITemplate[], scope: Scope) {
diff --git a/src/scope/icontext.ts b/src/scope/icontext.ts
index e156f84d2..62a791325 100644
--- a/src/scope/icontext.ts
+++ b/src/scope/icontext.ts
@@ -1,4 +1,4 @@
 export default interface IContext {
-    [key: string]: any;
-    liquid_method_missing?: (key: string) => any;
-}
\ No newline at end of file
+  [key: string]: any;
+  liquid_method_missing?: (key: string) => any; // eslint-disable-line
+}
diff --git a/src/scope/scope.ts b/src/scope/scope.ts
index 93dd5b699..6aaa1a71f 100644
--- a/src/scope/scope.ts
+++ b/src/scope/scope.ts
@@ -4,7 +4,7 @@ import * as lexical from '../parser/lexical'
 import assert from '../util/assert'
 import { NormalizedFullOptions, applyDefault } from '../liquid-options'
 import BlockMode from './block-mode'
-import IContext from './icontext';
+import IContext from './icontext'
 
 export default class Scope {
   opts: NormalizedFullOptions
diff --git a/src/template/filter/filter-impl.ts b/src/template/filter/filter-impl.ts
index 5fb626f07..1e8a3a566 100644
--- a/src/template/filter/filter-impl.ts
+++ b/src/template/filter/filter-impl.ts
@@ -1,3 +1 @@
-type FilterImpl = (value: any, ...args: any[]) => any
-
-export default FilterImpl
+export type FilterImpl = (value: any, ...args: any[]) => any
diff --git a/src/template/filter/filter.ts b/src/template/filter/filter.ts
index 578daf913..f4f294c2f 100644
--- a/src/template/filter/filter.ts
+++ b/src/template/filter/filter.ts
@@ -2,7 +2,7 @@ import assert from 'src/util/assert'
 import * as lexical from 'src/parser/lexical'
 import { evalValue } from 'src/render/syntax'
 import Scope from 'src/scope/scope'
-import FilterImpl from './filter-impl'
+import { FilterImpl } from './filter-impl'
 
 const valueRE = new RegExp(`${lexical.value.source}`, 'g')
 
diff --git a/src/template/tag/hash.ts b/src/template/tag/hash.ts
index 87543069d..0cdfc1030 100644
--- a/src/template/tag/hash.ts
+++ b/src/template/tag/hash.ts
@@ -1,6 +1,6 @@
 import { hashCapture } from 'src/parser/lexical'
 import { evalValue } from 'src/render/syntax'
-import Scope from 'src/scope/scope';
+import Scope from 'src/scope/scope'
 
 /**
  * Key-Value Pairs Representing Tag Arguments
diff --git a/src/util/error.ts b/src/util/error.ts
index 241e0abac..3b81ceda3 100644
--- a/src/util/error.ts
+++ b/src/util/error.ts
@@ -1,5 +1,4 @@
 import * as _ from './underscore'
-import { __extends } from 'tslib'
 import Token from 'src/parser/token'
 import ITemplate from 'src/template/itemplate'
 
@@ -11,7 +10,7 @@ abstract class LiquidError extends Error {
     this.originalError = err
     this.token = token
   }
-  protected update() {
+  protected update () {
     const err = this.originalError
     const context = mkContext(this.token)
     this.message = mkMessage(err.message, this.token)
diff --git a/src/util/promise.ts b/src/util/promise.ts
index d62c71b74..8f225ee62 100644
--- a/src/util/promise.ts
+++ b/src/util/promise.ts
@@ -5,8 +5,8 @@
  * The iteratee is invoked with three arguments: (value, index, iterable).
  */
 export function mapSeries<T1, T2> (
-    iterable: T1[],
-    iteratee: (item: T1, idx: number, iterable: T1[]) => Promise<T2> | T2
+  iterable: T1[],
+  iteratee: (item: T1, idx: number, iterable: T1[]) => Promise<T2> | T2
 ): Promise<T2[]> {
   let ret = Promise.resolve(0)
   const result: T2[] = []
diff --git a/src/util/strftime.ts b/src/util/strftime.ts
index c14e89178..cd604520a 100644
--- a/src/util/strftime.ts
+++ b/src/util/strftime.ts
@@ -179,6 +179,6 @@ export default function (d: Date, format: string) {
     // Add the format code
     const ch = results[0].charAt(1)
     const func = formatCodes[ch]
-    output += func ? func.call(null, d) : '%' + ch
+    output += func ? func(d) : '%' + ch
   }
 }
diff --git a/src/util/underscore.ts b/src/util/underscore.ts
index c7345e568..f1d841a69 100644
--- a/src/util/underscore.ts
+++ b/src/util/underscore.ts
@@ -77,10 +77,10 @@ export function isError (value: any): boolean {
  * @param {Function} iteratee The function invoked per iteration.
  * @return {Object} Returns object.
  */
-export function forOwn <T>(
+export function forOwn <T> (
   object: {[key: string]: T} | undefined,
   iteratee: ((val: T, key: string, obj: {[key: string]: T}) => boolean | void)
-  ) {
+) {
   object = object || {}
   for (const k in object) {
     if (object.hasOwnProperty(k)) {
diff --git a/test/unit/builtin/tags/for.ts b/test/unit/builtin/tags/for.ts
index 0d12bcb95..7f19d6450 100644
--- a/test/unit/builtin/tags/for.ts
+++ b/test/unit/builtin/tags/for.ts
@@ -1,7 +1,7 @@
 import Liquid from 'src/liquid'
 import { expect, use } from 'chai'
 import * as chaiAsPromised from 'chai-as-promised'
-import IContext from 'src/scope/icontext';
+import IContext from 'src/scope/icontext'
 
 use(chaiAsPromised)
 
diff --git a/test/unit/liquid/liquid-options.ts b/test/unit/liquid/liquid-options.ts
index 6d1dd55af..f625c7332 100644
--- a/test/unit/liquid/liquid-options.ts
+++ b/test/unit/liquid/liquid-options.ts
@@ -4,11 +4,11 @@ import { expect } from 'chai'
 describe('LiquidOptions', function () {
   describe('#normalize ()', function () {
     it('should normalize string typed root array', function () {
-      const options = normalize({root: 'foo'})
+      const options = normalize({ root: 'foo' })
       expect(options.root).to.eql(['foo'])
     })
     it('should normalize null typed root as empty array', function () {
-      const options = normalize({root: null} as any)
+      const options = normalize({ root: null } as any)
       expect(options.root).to.eql([])
     })
   })
diff --git a/test/unit/scope/scope.ts b/test/unit/scope/scope.ts
index dd4428390..d851adebb 100644
--- a/test/unit/scope/scope.ts
+++ b/test/unit/scope/scope.ts
@@ -1,6 +1,6 @@
 import * as chai from 'chai'
 import Scope from 'src/scope/scope'
-import IContext from 'src/scope/icontext';
+import IContext from 'src/scope/icontext'
 
 const expect = chai.expect