feat: detect circular imports

Author: dominykas

lib/travis/imports.js

@@ -13,7 +13,7 @@ const internals = {
 };
 
 
-internals.normalizeImports = (travisYaml, { relativeTo }) => {
+internals.normalizeImports = (travisYaml, { relativeTo, breadcrumb }) => {
 
     const context = relativeTo ? relativeTo.source : '.travis.yml';
 
@@ -49,6 +49,11 @@ internals.normalizeImports = (travisYaml, { relativeTo }) => {
                 throw new Error(`Importing at commitish unsupported in ${context}: ${original}`);
             }
 
+            const alreadyImported = breadcrumb.indexOf(entry.source);
+            if (alreadyImported >= 0) {
+                throw new Error(`Circular dependency ${entry.source} requested by ${context} (already imported at ${breadcrumb[alreadyImported - 1]})`);
+            }
+
             return entry;
         })
         .filter((entry) => !entry.if); // @todo: log a warning
@@ -71,13 +76,13 @@ internals.loadSource = async (source, { loadFile }) => {
 };
 
 
-exports.apply = async (yaml, { loadFile, relativeTo }) => {
+exports.apply = async (yaml, { loadFile, relativeTo, breadcrumb = ['.travis.yml'] }) => {
 
     if (!yaml.import) {
         return;
     }
 
-    const imports = internals.normalizeImports(yaml, { relativeTo });
+    const imports = internals.normalizeImports(yaml, { relativeTo, breadcrumb });
 
     for (const entry of imports) {
 
@@ -88,7 +93,7 @@ exports.apply = async (yaml, { loadFile, relativeTo }) => {
             json: true
         });
 
-        await exports.apply(imported, { loadFile, relativeTo: entry });
+        await exports.apply(imported, { loadFile, relativeTo: entry, breadcrumb: [...breadcrumb, entry.source] });
 
         delete imported.import;
 

test/fixtures/index.js

@@ -93,6 +93,7 @@ module.exports = class TestContext {
         if (partials) {
             Fs.mkdirSync(Path.join(this.path, 'partials'));
             const partialYmls = [
+                'circular.yml',
                 'commitish.yml',
                 'indirect-node-14.yml',
                 'merge-invalid.yml',

test/fixtures/travis-ymls/testing-imports/circular.yml

@@ -0,0 +1,3 @@
+language: node_js
+import:
+  - source: partials/circular.yml

test/fixtures/travis-ymls/testing-imports/partials/circular.yml

@@ -0,0 +1,3 @@
+language: node_js
+import:
+  - source: partials/circular.yml

test/travis.js

@@ -278,6 +278,16 @@ describe('.travis.yml parsing', () => {
 
         await expect(NodeSupport.detect({ path: fixture.path })).to.reject('Importing at commitish unsupported in partials/commitish.yml: partials/node-14.yml@main');
     });
+
+    it('throws when importing a circular dependency', async () => {
+
+        await fixture.setupRepoFolder({
+            partials: true,
+            travisYml: `testing-imports/circular.yml`
+        });
+
+        await expect(NodeSupport.detect({ path: fixture.path })).to.reject('Circular dependency partials/circular.yml requested by partials/circular.yml (already imported at .travis.yml)');
+    });
 });
 
 describe('Travis merging algorithms', () => {