fix(function-call): make lambda function calls chainable

src/__tests__/interpreter.test.js

@@ -2,6 +2,7 @@
 
 import execute from '../interpreter'
 import compile from '../compiler'
+import parse from '../parsers/parser'
 
 const tests = [
   {
@@ -130,6 +131,21 @@ const tests = [
     sourceCode: `map \\" "`,
     input: ['Hello', 'World'],
     output: [' ', ' ']
+  },
+  {
+    sourceCode: `{"original": $.foo} | {"new": $}`,
+    input: { foo: 42 },
+    output: { new: { original: 42 } }
+  },
+  {
+    sourceCode: `map $ => {"original": $.foo} | map $=> {"new": $}`,
+    input: [{ foo: 42 }, { foo: 'hello' }],
+    output: [{ new: { original: 42 } }, { new: { original: 'hello' } }]
+  },
+  {
+    sourceCode: `map $ => {"original": $.foo} | "foo"`,
+    input: [{ foo: 42 }, { foo: 'hello' }],
+    output: 'foo'
   }
 ]
 
@@ -151,6 +167,10 @@ describe('interpreter', () => {
       it(`correct target code ${sourceCode}`, () => {
         expect(compile(sourceCode)).toMatchSnapshot()
       })
+
+      it(`correct target tree ${sourceCode}`, () => {
+        expect(parse(sourceCode)).toMatchSnapshot()
+      })
     }
   )
 

src/generators/__tests__/functionCallLambda.test.js

@@ -6,7 +6,7 @@ describe('functionCallLambda generator', () => {
   it('generates correct code', () => {
     const fakeGenerator = (
       { type } // eslint-disable-line flowtype/require-parameter-type
-    ): string => '[]'
+    ): string => 'input[0]'
     expect(
       functionCallLambda(fakeGenerator)({
         type: 'functionCallLambda',
@@ -21,6 +21,6 @@ describe('functionCallLambda generator', () => {
           }
         }
       })
-    ).toEqual('_.foo(function(input) {return []})(input)')
+    ).toEqual('(_.foo(function(input) {return input[0]})(input))')
   })
 })

src/generators/functionCallLambda.js

@@ -11,6 +11,6 @@ export default (
 ): (FunctionCallLambdaNodeType => GeneratedCodeType) => ({
   value
 }: FunctionCallLambdaNodeType): GeneratedCodeType =>
-  `_.${value.left.value}(function(input) {return ${Generator(
+  `(_.${value.left.value}(function(input) {return ${Generator(
     value.right
-  )}})(input)`
+  )}})(input))`

src/parsers/functionCall.js

@@ -2,17 +2,25 @@
 
 import Parsimmon from 'parsimmon'
 
-import type { FunctionCallNodeType, NodeType, IdentifierNodeType } from '../types'
+import type {
+  FunctionCallNodeType,
+  NodeType,
+  IdentifierNodeType
+} from '../types'
 
 const FunctionCallParser = Parsimmon.lazy((): mixed => {
-  const ProgramParser = require('./program').default
+  const TupleParser = require('./tuple/tuple').default
   const IdentifierParser = require('./identifier').default
   return Parsimmon.seq(
     IdentifierParser,
     Parsimmon.optWhitespace,
-    ProgramParser
+    TupleParser
   ).map(
-    ([left, _, right]: [IdentifierNodeType, mixed, NodeType]): FunctionCallNodeType => ({
+    ([left, _, right]: [
+      IdentifierNodeType,
+      mixed,
+      NodeType
+    ]): FunctionCallNodeType => ({
       type: 'functionCall',
       value: {
         left,

src/parsers/functionCallLambda.js

@@ -9,14 +9,14 @@ import type {
 } from '../types'
 
 const FunctionCallLambdaParser = Parsimmon.lazy((): mixed => {
-  const ProgramParser = require('./program').default
+  const TupleParser = require('./tuple/tuple').default
   const IdentifierParser = require('./identifier').default
   return Parsimmon.seq(
     IdentifierParser,
     Parsimmon.optWhitespace,
     Parsimmon.alt(Parsimmon.regexp(/\$\s*=>\s*/), Parsimmon.string('\\')),
     Parsimmon.optWhitespace,
-    ProgramParser
+    TupleParser
   ).map(
     ([left, _, __, ___, right]: [
       IdentifierNodeType,

src/parsers/program.js

@@ -4,16 +4,9 @@ import Parsimmon from 'parsimmon'
 import TupleParser from './tuple/tuple'
 import PipeParser from './pipe/pipe'
 import type { NodeType } from '../types'
-import FunctionCallParser from './functionCall'
-import FunctionCallLambdaParser from './functionCallLambda'
 
 export default Parsimmon.seq(
   Parsimmon.optWhitespace,
-  Parsimmon.alt(
-    FunctionCallLambdaParser,
-    FunctionCallParser,
-    PipeParser,
-    TupleParser
-  ),
+  Parsimmon.alt(PipeParser, TupleParser),
   Parsimmon.optWhitespace
 ).map((value: [mixed, NodeType, mixed]): NodeType => value[1])

src/parsers/section.js

@@ -1,8 +1,12 @@
 import Parsimmon from 'parsimmon'
 import ProjectionParser from './projection'
 import ProjectableParser from './projectable'
+import FunctionCallParser from './functionCall'
+import FunctionCallLambdaParser from './functionCallLambda'
 
 export default Parsimmon.alt(
+  FunctionCallLambdaParser,
+  FunctionCallParser,
   ProjectionParser,
   ProjectableParser
 )