wip(feat): add pattern for escaping token lookup()

Ref: #14

Author: mdeltito

lib/chain.js

@@ -5,7 +5,8 @@ const {object} = require('@logdna/stdlib')
 const typeOf = require('./lang/type-of.js')
 const builtins = require('./actions/index.js')
 const {Parser, Lexer, Visitor} = require('./parser/index.js')
-const {BANG, HASH} = require('./parser/tokens.js')
+const {BANG, HASH, DASH} = require('./parser/tokens.js')
+const ESCAPE_TOKENS = new Set([DASH.name])
 const PARSE_TOKENS = new Set([BANG.name, HASH.name])
 
 const lookup = Symbol('lookup')
@@ -113,6 +114,10 @@ module.exports = class SetupChain {
     if (!lexed.tokens.length) return this.visitor.wrapLiteral(str)
 
     const firstToken = lexed.tokens[0]
+    if (ESCAPE_TOKENS.has(firstToken.tokenType.name)) {
+      return this.visitor.wrapLiteral(str.slice(1))
+    }
+
     if (!PARSE_TOKENS.has(firstToken.tokenType.name)) {
       return this.visitor.wrapLiteral(str)
     }
@@ -155,7 +160,6 @@ module.exports = class SetupChain {
         const fn = this.actions[key]
         this.state[label || key] = await fn.apply(this, rest)
       } catch (err) {
-        console.error(err)
         const error = new Error(`Setup Chain error in ${key}`)
         error.stack = err.stack
         error.chain_params = task

lib/parser/tokens.js

@@ -7,6 +7,11 @@ const BANG = createToken({
 , pattern: /!/
 })
 
+const DASH = createToken({
+  name: 'dash'
+, pattern: /-/
+})
+
 const COMMA = createToken({
   name: 'comma'
 , pattern: ','
@@ -54,6 +59,7 @@ const WHITE_SPACE = createToken({
 })
 
 BANG.LABEL = '!'
+DASH.LABEL = '-'
 HASH.LABEL = '#'
 COMMA.LABEL = ','
 COLON.LABEL = ':'
@@ -66,6 +72,7 @@ module.exports = {
 , DOT
 , HASH
 , BANG
+, DASH
 , LPAREN
 , RPAREN
 , COMMA

test/integration/chain.js

@@ -207,6 +207,27 @@ test('Setup chain', async (t) => {
     }
   })
 
+  t.test('escape control', async (t) => {
+    class EscapeChain extends Chain {
+      constructor(state) {
+        super(state)
+      }
+
+      $test(arg) {
+        return arg
+      }
+    }
+
+    const chain = new EscapeChain({f00: 'wrong'})
+    chain.set('color', '-#f00')
+    chain.set('rand', '-!random')
+    chain.set('complex', '!test("-#foo")')
+    const state = await chain.execute()
+    t.equal(state.color, '#f00')
+    t.equal(state.rand, '!random')
+    t.equal(state.complex, '#foo')
+  })
+
   t.test('Default SetupChain (no actions, state); Only built-ins', async (t) => {
     const chain = new Chain(null, null)
     t.same(chain.state, {}, 'Empty state')