Cleanup file formatters. (#759)

* Clean up frontmatter formatter.

* Move `formatToExtension`.

* Use plain objects for file formatters.

* Use same parsers for files and frontmatter.

We want to use our file parsers for frontmatter, instead of the builtin
ones, as they process some formats (images, dates) properly.

* Cleanup YAML frontmatter parser code.

src/formats/__tests__/frontmatter.spec.js

@@ -1,9 +1,7 @@
-import Frontmatter from '../frontmatter';
+import FrontmatterFormatter from '../frontmatter';
 
 jest.mock("../../valueObjects/AssetProxy.js");
 
-const FrontmatterFormatter = new Frontmatter();
-
 describe('Frontmatter', () => {
   it('should parse YAML with --- delimiters', () => {
     expect(

src/formats/formats.js

@@ -1,12 +1,15 @@
-import YAML from './yaml';
-import TOML from './toml';
-import JSONFormatter from './json';
-import Frontmatter from './frontmatter';
+import yamlFormatter from './yaml';
+import tomlFormatter from './toml';
+import jsonFormatter from './json';
+import FrontmatterFormatter from './frontmatter';
 
-const yamlFormatter = new YAML();
-const tomlFormatter = new TOML();
-const jsonFormatter = new JSONFormatter();
-const FrontmatterFormatter = new Frontmatter();
+export const formatToExtension = format => ({
+  markdown: 'md',
+  yaml: 'yml',
+  toml: 'toml',
+  json: 'json',
+  html: 'html',
+}[format]);
 
 function formatByType(type) {
   // Right now the only type is "editorialWorkflow" and

src/formats/frontmatter.js

@@ -1,12 +1,11 @@
 import matter from 'gray-matter';
-import TOML from './toml';
-import YAML from './yaml';
-
-const tomlFormatter = new TOML();
+import tomlFormatter from './toml';
+import yamlFormatter from './yaml';
+import jsonFormatter from './json';
 
 const parsers = {
-  toml: tomlFormatter.fromFile.bind(tomlFormatter),
-  json: (input) => {
+  toml: input => tomlFormatter.fromFile(input),
+  json: input => {
     let JSONinput = input.trim();
     // Fix JSON if leading and trailing brackets were trimmed.
     if (JSONinput.substr(0, 1) !== '{') {
@@ -15,7 +14,11 @@ const parsers = {
     if (JSONinput.substr(-1) !== '}') {
       JSONinput = JSONinput + '}';
     }
-    return matter.engines.json.parse(JSONinput);
+    return jsonFormatter.fromFile(JSONinput);
+  },
+  yaml: {
+    parse: input => yamlFormatter.fromFile(input),
+    stringify: (metadata, { sortedKeys }) => yamlFormatter.toFile(metadata, sortedKeys),
   },
 }
 
@@ -37,31 +40,20 @@ function inferFrontmatterFormat(str) {
   }
 }
 
-export default class Frontmatter {
+export default {
   fromFile(content) {
     const result = matter(content, { engines: parsers, ...inferFrontmatterFormat(content) });
-    const data = result.data;
-    data.body = result.content;
-    return data;
-  }
+    return {
+      ...result.data,
+      body: result.content,
+    };
+  },
 
   toFile(data, sortedKeys) {
-    const meta = {};
-    let body = '';
-    Object.keys(data).forEach((key) => {
-      if (key === 'body') {
-        body = data[key];
-      } else {
-        meta[key] = data[key];
-      }
-    });
+    const { body, ...meta } = data;
 
     // always stringify to YAML
-    const parser = {
-      stringify(metadata) {
-        return new YAML().toFile(metadata, sortedKeys);
-      },
-    };
-    return matter.stringify(body, meta, { language: "yaml", delimiters: "---", engines: { yaml: parser } });
+    // `sortedKeys` is not recognized by gray-matter, so it gets passed through to the parser
+    return matter.stringify(body, meta, { engines: parsers, language: "yaml", delimiters: "---", sortedKeys });
   }
 }

src/formats/json.js

@@ -1,7 +1,7 @@
-export default class JSONFormatter {
+export default {
   fromFile(content) {
     return JSON.parse(content);
-  }
+  },
 
   toFile(data) {
     return JSON.stringify(data);

src/formats/toml.js

@@ -15,10 +15,10 @@ const outputReplacer = (key, value) => {
   return false;
 };
 
-export default class TOML {
+export default {
   fromFile(content) {
     return toml.parse(content);
-  }
+  },
 
   toFile(data, sortedKeys = []) {
     return tomlify.toToml(data, { replace: outputReplacer, sort: sortKeys(sortedKeys) });

src/formats/yaml.js

@@ -36,10 +36,10 @@ const OutputSchema = new yaml.Schema({
   explicit: yaml.DEFAULT_SAFE_SCHEMA.explicit,
 });
 
-export default class YAML {
+export default {
   fromFile(content) {
     return yaml.safeLoad(content);
-  }
+  },
 
   toFile(data, sortedKeys = []) {
     return yaml.safeDump(data, { schema: OutputSchema, sortKeys: sortKeys(sortedKeys) });

src/reducers/collections.js

@@ -4,6 +4,7 @@ import consoleError from '../lib/consoleError';
 import { CONFIG_SUCCESS } from '../actions/config';
 import { FILES, FOLDER } from '../constants/collectionTypes';
 import { INFERABLE_FIELDS } from '../constants/fieldInference';
+import { formatToExtension } from '../formats/formats';
 
 const collections = (state = null, action) => {
   const configCollections = action.payload && action.payload.collections;
@@ -26,14 +27,6 @@ const collections = (state = null, action) => {
   }
 };
 
-const formatToExtension = format => ({
-  markdown: 'md',
-  yaml: 'yml',
-  toml: 'toml',
-  json: 'json',
-  html: 'html',
-}[format]);
-
 const selectors = {
   [FOLDER]: {
     entryExtension(collection) {