feat(cov): add nyc instrument passthrough

README.md

@@ -170,6 +170,14 @@ You can pass any mocha argv.
 - `-x` add dir ignore coverage, support multiple argv
 - `--prerequire` prerequire files for coverage instrument, you can use this options if load files slowly when call `mm.app` or `mm.cluster`
 - `--typescript` / `--ts` enable typescript support, default to `false`, if true, will auto add `.ts` extension and ignore `typings` and `d.ts`.
+- `--nyc` nyc instruments passthrough. you can use this to overwrite egg-bin's default nyc instruments and add additional ones.
+  >if you want to add addtional nyc reporters, you need to use this rather than add `reporter` key in `.nycrc` because:
+  >* when same key exists in `.nycrc` and cmd instruments, nyc prefers instrument.
+  >* egg-bin have some default instruments passed to nyc like `-r` and `--temp-directory`
+  ```bash
+  egg-bin cov --nyc="-r teamcity -r text"
+  ```
+
 - also support all test params above.
 
 #### environment

lib/cmd/cov.js

@@ -25,6 +25,11 @@ class CovCommand extends Command {
         description: 'prerequire files for coverage instrument',
         type: 'boolean',
       },
+      nyc: {
+        description: 'nyc instruments passthrough',
+        type: 'string',
+        default: '--temp-directory ./node_modules/.nyc_output -r text-summary -r json-summary -r json -r lcov',
+      },
     };
 
     // you can add ignore dirs here
@@ -102,11 +107,6 @@ class CovCommand extends Command {
   getCovArgs(context) {
     let covArgs = [
       // '--show-process-tree',
-      '--temp-directory', './node_modules/.nyc_output',
-      '-r', 'text-summary',
-      '-r', 'json-summary',
-      '-r', 'json',
-      '-r', 'lcov',
     ];
 
     // typescript support
@@ -116,6 +116,13 @@ class CovCommand extends Command {
       this.addExclude('**/*.d.ts');
     }
 
+    // nyc args passthrough
+    const nycArgs = context.argv.nyc;
+    context.argv.nyc = undefined;
+    if (nycArgs) {
+      covArgs = covArgs.concat(nycArgs.split(' '));
+    }
+
     for (const exclude of this[EXCLUDES]) {
       covArgs.push('-x');
       covArgs.push(exclude);

test/lib/cmd/cov.test.js

@@ -198,4 +198,15 @@ describe('test/lib/cmd/cov.test.js', () => {
       .expect('code', 0)
       .end();
   });
+
+  it('should passthrough nyc args', done => {
+    mm(process.env, 'TESTS', 'test/**/*.test.js');
+    mm(process.env, 'NYC_CWD', cwd);
+    coffee.fork(eggBin, [ 'cov', '--nyc=-r teamcity -r text' ], { cwd })
+      // .debug()
+      .expect('stdout', /should success/)
+      .expect('stdout', /##teamcity\[blockOpened name='Code Coverage Summary'\]/)
+      .expect('stdout', /##teamcity\[blockClosed name='Code Coverage Summary'\]/)
+      .end(done);
+  });
 });