Support multiple language mappings

This will store running kernels by the language from their kernel spec.
It also makes sure that all names are normalized to lower case to avoid confusion.

Fixes #684

lib/kernel-manager.js

@@ -165,15 +165,12 @@ class KernelManager {
     });
   }
 
-  kernelSpecProvidesLanguage(kernelSpec, language) {
+  kernelSpecProvidesLanguage(kernelSpec, grammarLanguage) {
     const kernelLanguage = kernelSpec.language;
     const mappedLanguage = Config.getJson("languageMappings")[kernelLanguage];
 
-    if (mappedLanguage) {
-      return mappedLanguage === language;
-    }
-
-    return kernelLanguage.toLowerCase() === language;
+    return mappedLanguage === grammarLanguage ||
+      kernelLanguage === grammarLanguage;
   }
 
   getKernelSpecsFromSettings() {

lib/kernel.js

@@ -3,7 +3,7 @@
 import { Emitter } from "atom";
 import { observable, action } from "mobx";
 
-import { grammarToLanguage, log } from "./utils";
+import { log } from "./utils";
 import store from "./store";
 
 import WatchSidebar from "./watch-sidebar";
@@ -31,8 +31,7 @@ export default class Kernel {
     this.grammar = grammar;
     this.watchSidebar = new WatchSidebar(this);
 
-    // $FlowFixMe Since grammar is defined, grammarToLanguage will return a string
-    this.language = grammarToLanguage(grammar);
+    this.language = kernelSpec.language.toLowerCase();
     this.displayName = kernelSpec.display_name;
   }
 

lib/utils.js

@@ -6,6 +6,7 @@ import _ from "lodash";
 import os from "os";
 import path from "path";
 
+import Config from "./config";
 import store from "./store";
 
 export function reactFactory(
@@ -25,7 +26,16 @@ export function reactFactory(
 }
 
 export function grammarToLanguage(grammar: ?atom$Grammar) {
-  return grammar ? grammar.name.toLowerCase() : null;
+  if (!grammar) return null;
+  const grammarLanguage = grammar.name.toLowerCase();
+
+  const mappings = Config.getJson("languageMappings");
+  const kernelLanguage = _.findKey(
+    mappings,
+    l => l.toLowerCase() === grammarLanguage
+  );
+
+  return kernelLanguage ? kernelLanguage.toLowerCase() : grammarLanguage;
 }
 
 const markupGrammars = new Set([

spec/utils-spec.js

@@ -14,10 +14,30 @@ import {
 } from "./../lib/utils";
 
 describe("utils", () => {
-  it("grammarToLanguage", () => {
-    expect(grammarToLanguage({ name: "Kernel Name" })).toEqual("kernel name");
-    expect(grammarToLanguage(null)).toBeNull();
-    expect(grammarToLanguage(undefined)).toBeNull();
+  describe("grammarToLanguage", () => {
+    it("should return null if no rammar given", () => {
+      expect(grammarToLanguage()).toBeNull();
+      expect(grammarToLanguage(null)).toBeNull();
+      expect(grammarToLanguage(undefined)).toBeNull();
+    });
+
+    it("should return language from grammar", () => {
+      expect(grammarToLanguage({ name: "Kernel Name" })).toEqual("kernel name");
+    });
+
+    it("should return respect languageMappings", () => {
+      atom.config.set(
+        "Hydrogen.languageMappings",
+        `{"Kernel Language": "Grammar Language"}`
+      );
+      expect(grammarToLanguage({ name: "Grammar Language" })).toEqual(
+        "kernel language"
+      );
+      expect(grammarToLanguage({ name: "Kernel Language" })).toEqual(
+        "kernel language"
+      );
+      atom.config.set("Hydrogen.languageMappings", "");
+    });
   });
 
   it("reactFactory", () => {