feat(api): Add basic API features

The core API methods have been added

src/index.coffee

@@ -0,0 +1,25 @@
+{Service} = require './service/service.coffee'
+{DataQuery} = require './data/data-query.coffee'
+{MetadataQuery} = require './metadata/metadata-query.coffee'
+{UrlGenerator} = require './utils/url-generator.coffee'
+
+getService = (id) ->
+  if typeof id is 'object'
+    return Service.from id
+  if typeof id is 'string' and Service[id]
+    return Service[id]
+  throw Error "Unknown service #{id}"
+
+getDataQuery = (opts) ->
+  return DataQuery.from opts
+
+getMetadataQuery = (opts) ->
+  return MetadataQuery.from opts
+
+getUrl = (query, service) ->
+  return new UrlGenerator().getUrl query, service
+
+exports.getService = getService
+exports.getDataQuery = getDataQuery
+exports.getMetadataQuery = getMetadataQuery
+exports.getUrl = getUrl

test/index.test.coffee

@@ -0,0 +1,140 @@
+sdmxrest = require '../src/index.coffee'
+{ServiceType} = require '../src/service/service-type.coffee'
+
+describe 'API', ->
+
+  it 'should have the expected functions', ->
+    sdmxrest.should.have.property 'getService'
+    sdmxrest.should.have.property 'getDataQuery'
+    sdmxrest.should.have.property 'getMetadataQuery'
+    sdmxrest.should.have.property 'getUrl'
+
+  it 'should offer to get an existing service', ->
+    service = sdmxrest.getService 'ECB'
+    service.should.be.an 'object'
+    service.should.have.property('id').that.equals 'ECB'
+    service.should.have.property('name').that.equals 'European Central Bank'
+    service.should.have.property('url').that.contains 'sdw-wsrest'
+    service.should.have.property('api').that.is.not.undefined
+
+  it 'should offer to create a service from properties', ->
+    input = {
+      id: 'TEST'
+      url: 'http://test.com'
+    }
+    service = sdmxrest.getService input
+    service.should.be.an 'object'
+    service.should.have.property('id').that.equals input.id
+    service.should.have.property('name').that.is.undefined
+    service.should.have.property('url').that.equals input.url
+    service.should.have.property('api').that.equals ServiceType.LATEST
+
+  it 'should fail if the service is unknown', ->
+    try
+      sdmxrest.getService 'UNKNOWN'
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Unknown service'
+
+  it 'should fail if the input to service is not of the expected type', ->
+    try
+      sdmxrest.getService 2
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Unknown service'
+
+    try
+      sdmxrest.getService undefined
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Unknown service'
+
+  it 'should offer to create a data query from properties', ->
+    input = {
+      flow: 'EXR'
+      key: 'A..EUR.SP00.A'
+    }
+    query = sdmxrest.getDataQuery input
+    query.should.be.an 'object'
+    query.should.have.property('flow').that.equals input.flow
+    query.should.have.property('key').that.equals input.key
+    query.should.have.property('provider').that.equals 'all'
+    query.should.have.property('start').that.is.undefined
+    query.should.have.property('end').that.is.undefined
+    query.should.have.property('updatedAfter').that.is.undefined
+    query.should.have.property('firstNObs').that.is.undefined
+    query.should.have.property('lastNObs').that.is.undefined
+    query.should.have.property('obsDimension').that.equals 'TIME_PERIOD'
+    query.should.have.property('detail').that.equals 'full'
+    query.should.have.property('history').that.is.false
+
+  it 'should fail if input to data query is not of the expected type', ->
+    try
+      sdmxrest.getDataQuery undefined
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Not a valid data query'
+
+    try
+      sdmxrest.getDataQuery {test: 'TEST'}
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Not a valid data query'
+
+  it 'should offer to create a metadata query from properties', ->
+    input = {
+      resource: 'codelist'
+      id: 'CL_FREQ'
+    }
+    query = sdmxrest.getMetadataQuery input
+    query.should.be.an 'object'
+    query.should.have.property('resource').that.equals input.resource
+    query.should.have.property('id').that.equals input.id
+    query.should.have.property('agency').that.equals 'all'
+    query.should.have.property('version').that.equals 'latest'
+    query.should.have.property('item').that.equals 'all'
+    query.should.have.property('detail').that.equals 'full'
+    query.should.have.property('references').that.equals 'none'
+
+  it 'should fail if input to metadata query is not of the expected type', ->
+    try
+      sdmxrest.getMetadataQuery undefined
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Not a valid metadata query'
+
+    try
+      sdmxrest.getMetadataQuery {test: 'TEST'}
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Not a valid metadata query'
+
+  it 'should offer to create a URL from a query and a service', ->
+    query = sdmxrest.getDataQuery {flow: 'EXR', key: 'A.CHF.NOK.SP00.A'}
+    service = sdmxrest.getService 'ECB'
+    url = sdmxrest.getUrl query, service
+    url.should.be.a 'string'
+    url.should.contain service.url
+    url.should.contain query.flow
+    url.should.contain query.key
+
+  it 'should fail if input to URL are not of the expected types', ->
+    try
+      sdmxrest.getUrl undefined, sdmxrest.getService 'ECB'
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'not a valid SDMX data or metadata query'
+
+    query = sdmxrest.getDataQuery {flow: 'EXR', key: 'A.CHF.NOK.SP00.A'}
+
+    try
+      sdmxrest.getUrl query, sdmxrest.getService 'TEST'
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'Unknown service'
+
+    try
+      sdmxrest.getUrl query
+      assert.fail 'An error should have been triggered'
+    catch error
+      error.message.should.contain 'not a valid service'