diff --git a/lighthouse-core/fraggle-rock/config/filters.js b/lighthouse-core/fraggle-rock/config/filters.js
index 4b9c0027f71c..f4beff315096 100644
--- a/lighthouse-core/fraggle-rock/config/filters.js
+++ b/lighthouse-core/fraggle-rock/config/filters.js
@@ -294,6 +294,8 @@ function filterConfigByExplicitFilters(config, filters) {
     baseAuditIds = getAuditIdsInCategories(config.categories, onlyCategories);
   } else if (onlyAudits) {
     baseAuditIds = new Set();
+  } else if (!config.categories || !Object.keys(config.categories).length) {
+    baseAuditIds = new Set(config.audits?.map(audit => audit.implementation.meta.id));
   }
 
   const auditIdsToKeep = new Set(
diff --git a/lighthouse-core/fraggle-rock/gather/navigation-runner.js b/lighthouse-core/fraggle-rock/gather/navigation-runner.js
index bdcefbc27a80..e0d8e245f8e7 100644
--- a/lighthouse-core/fraggle-rock/gather/navigation-runner.js
+++ b/lighthouse-core/fraggle-rock/gather/navigation-runner.js
@@ -327,6 +327,7 @@ async function navigationGather(requestor, options) {
   const artifacts = await Runner.gather(
     async () => {
       let {page} = options;
+      const normalizedRequestor = isCallback ? requestor : URL.normalizeUrl(requestor);
 
       // For navigation mode, we shouldn't connect to a browser in audit mode,
       // therefore we connect to the browser in the gatherFn callback.
@@ -340,7 +341,7 @@ async function navigationGather(requestor, options) {
       const context = {
         driver,
         config,
-        requestor: isCallback ? requestor : URL.normalizeUrl(requestor),
+        requestor: normalizedRequestor,
         options: internalOptions,
       };
       const {baseArtifacts} = await _setup(context);
diff --git a/lighthouse-core/test/fraggle-rock/config/filters-test.js b/lighthouse-core/test/fraggle-rock/config/filters-test.js
index 847bb57a3e7d..6fcc55515470 100644
--- a/lighthouse-core/test/fraggle-rock/config/filters-test.js
+++ b/lighthouse-core/test/fraggle-rock/config/filters-test.js
@@ -525,6 +525,34 @@ describe('Fraggle Rock Config Filtering', () => {
       });
     });
 
+    it('should keep all audits if there are no categories', () => {
+      config = {
+        ...config,
+        audits: [
+          ...audits,
+          {implementation: NavigationOnlyAudit, options: {}},
+        ],
+        categories: {},
+      };
+
+      const filtered = filters.filterConfigByExplicitFilters(config, {
+        onlyAudits: null,
+        onlyCategories: null,
+        skipAudits: null,
+      });
+      expect(filtered).toMatchObject({
+        navigations: [{id: 'firstPass'}],
+        artifacts: [{id: 'Snapshot'}, {id: 'Timespan'}],
+        audits: [
+          {implementation: SnapshotAudit},
+          {implementation: TimespanAudit},
+          {implementation: NavigationAudit},
+          {implementation: ManualAudit},
+          {implementation: NavigationOnlyAudit},
+        ],
+      });
+    });
+
     it('should preserve full-page-screenshot', async () => {
       config = (await initializeConfig(undefined, {gatherMode: 'navigation'})).config;
 
diff --git a/lighthouse-core/test/index-test.js b/lighthouse-core/test/index-test.js
index b09bcdf72144..779208003a32 100644
--- a/lighthouse-core/test/index-test.js
+++ b/lighthouse-core/test/index-test.js
@@ -37,6 +37,113 @@ describe('Module Tests', function() {
     assert.notEqual(lighthouseTraceCategories.length, 0);
   });
 
+  describe('lighthouse', () => {
+    it('should throw an error when the first parameter is not defined', async () => {
+      const resultPromise = lighthouse();
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the first parameter is an empty string', async () => {
+      const resultPromise = lighthouse('');
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the first parameter is not a string', async () => {
+      const resultPromise = lighthouse({});
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the second parameter is not an object', async () => {
+      const resultPromise = lighthouse('chrome://version', 'flags');
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the config is invalid', async () => {
+      const resultPromise = lighthouse('chrome://version', {}, {});
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the config contains incorrect audits', async () => {
+      const resultPromise = lighthouse('chrome://version', {}, {
+        passes: [{
+          gatherers: [
+            'script-elements',
+          ],
+        }],
+        audits: [
+          'fluff',
+        ],
+      });
+      await expect(resultPromise).rejects.toThrow();
+    });
+
+    it('should throw an error when the url is invalid', async () => {
+      const resultPromise = lighthouse('i-am-not-valid', {}, {});
+      await expect(resultPromise).rejects.toThrow('INVALID_URL');
+    });
+
+    it('should throw an error when the url is invalid protocol (file:///)', async () => {
+      const resultPromise = lighthouse('file:///a/fake/index.html', {}, {});
+      await expect(resultPromise).rejects.toThrow('INVALID_URL');
+    });
+
+    it('should return formatted LHR when given no categories', async () => {
+      const exampleUrl = 'https://www.reddit.com/r/nba';
+      const result = await lighthouse(exampleUrl, {
+        output: 'html',
+      }, {
+        settings: {
+          auditMode: TEST_DIR + '/fixtures/artifacts/perflog/',
+          formFactor: 'mobile',
+        },
+        artifacts: [
+          {id: 'MetaElements', gatherer: 'meta-elements'},
+        ],
+        audits: [
+          'viewport',
+        ],
+      });
+
+      assert.ok(/<html/.test(result.report), 'did not create html report');
+      assert.ok(result.artifacts.ViewportDimensions, 'did not set artifacts');
+      assert.ok(result.lhr.lighthouseVersion);
+      assert.ok(result.lhr.fetchTime);
+      assert.equal(result.lhr.finalUrl, exampleUrl);
+      assert.equal(result.lhr.requestedUrl, exampleUrl);
+      assert.equal(Object.values(result.lhr.categories).length, 0);
+      assert.ok(result.lhr.audits.viewport);
+      assert.strictEqual(result.lhr.audits.viewport.score, 0);
+      assert.ok(result.lhr.audits.viewport.explanation);
+      assert.ok(result.lhr.timing);
+      assert.ok(result.lhr.timing.entries.length > 3, 'timing entries not populated');
+    });
+
+    it('should specify the channel as node by default', async () => {
+      const exampleUrl = 'https://www.reddit.com/r/nba';
+      const result = await lighthouse(exampleUrl, {}, {
+        settings: {
+          auditMode: TEST_DIR + '/fixtures/artifacts/perflog/',
+          formFactor: 'mobile',
+        },
+        audits: [],
+      });
+      assert.equal(result.lhr.configSettings.channel, 'node');
+    });
+
+    it('lets consumers pass in a custom channel', async () => {
+      const exampleUrl = 'https://www.reddit.com/r/nba';
+      const result = await lighthouse(exampleUrl, {}, {
+        settings: {
+          auditMode: TEST_DIR + '/fixtures/artifacts/perflog/',
+          formFactor: 'mobile',
+          channel: 'custom',
+        },
+        audits: [],
+      });
+      assert.equal(result.lhr.configSettings.channel, 'custom');
+    });
+  });
+
   describe('legacyNavigation', () => {
     it('should throw an error when the first parameter is not defined', function() {
       return legacyNavigation()