Fix plugin cells (#2721)

Plugin cells have no variable type, but #2475 (accidentally) added
checking for that nonetheless.

CHANGELOG.md

@@ -3,6 +3,7 @@
 - Can now specify notebook iomd via a URL parameter with new or
  tryit endpoints (fixes #2565) (#2676)
 - Always show "Clear history" button in the Console dropdown (#2707)
+- Fix plugin cell parsing (#2721)
 
 # 0.18.0 (2020-01-22)
 

src/editor/actions/__tests__/fetch-cell-parser.test.js

@@ -173,6 +173,16 @@ const validFetchLines = [
  filePath: "https://d3js.org/d3.v5.min.js",
  isRelPath: false
  }
+ },
+ {
+ line:
+ "plugin: https://raw.githubusercontent.com/iodide-project/iodide-mermaid-plugin/master/plugin.json",
+ result: {
+ fetchType: "plugin",
+ filePath:
+ "https://raw.githubusercontent.com/iodide-project/iodide-mermaid-plugin/master/plugin.json",
+ isRelPath: false
+ }
  }
 ];
 describe("return valid results for valid fetch lines", () => {

src/editor/actions/fetch-cell-parser.js

@@ -60,9 +60,16 @@ export function missingFetchType(line) {
  return !line.trim().match(/^\w+\s*: /);
 }
 
+function getFetchType(line) {
+ return line
+ .trim()
+ .split(": ")[0]
+ .trimLeft();
+}
+
 export function validFetchType(line) {
- const fetchType = line.trim().split(": ")[0];
- return VALID_FETCH_TYPES.includes(fetchType.trimLeft());
+ const fetchType = getFetchType(line);
+ return VALID_FETCH_TYPES.includes(fetchType);
 }
 
 export function validVariableName(line) {
@@ -138,7 +145,7 @@ export function parseFetchCellLine(lineWithComments) {
  if (!validFetchUrl(line)) {
  return { error: "INVALID_FETCH_URL" };
  }
- if (!validVariableName(line)) {
+ if (getFetchType(line) !== "plugin" && !validVariableName(line)) {
  return { error: "INVALID_VARIABLE_NAME" };
  }