feat: add --tee-json option

Author: suo

src/lib.rs

@@ -10,6 +10,7 @@ use render::{render_lint_messages, render_lint_messages_json};
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::convert::TryFrom;
+use std::fs::OpenOptions;
 use std::sync::{Arc, Mutex};
 use std::thread;
 
@@ -155,6 +156,7 @@ pub fn do_lint(
     render_opt: RenderOpt,
     enable_spinners: bool,
     revision_opt: RevisionOpt,
+    tee_json: Option<String>,
 ) -> Result<i32> {
     debug!(
         "Running linters: {:?}",
@@ -255,6 +257,15 @@ pub fn do_lint(
         RenderOpt::Oneline => render_lint_messages_oneline(&mut stdout, &all_lints)?,
     };
 
+    if let Some(tee_json) = tee_json {
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .open(tee_json)
+            .context("Couldn't open file for --tee-json")?;
+        render_lint_messages_json(&mut file, &all_lints)?;
+    }
+
     if should_apply_patches {
         stdout.write_line("Successfully applied all patches.")?;
     }

src/main.rs

@@ -88,6 +88,11 @@ struct Args {
     /// application data (e.g. $XDG_DATA_HOME for UNIX systems.)
     #[clap(long, global = true)]
     data_path: Option<String>,
+
+
+    /// If set, output json to the provided path as well as the terminal.
+    #[clap(long, global=true)]
+    tee_json: Option<String>,
 }
 
 #[derive(Debug, Parser)]
@@ -211,6 +216,7 @@ fn do_main() -> Result<i32> {
         PathsOpt::Auto
     };
 
+
     let res = match cmd {
         SubCommand::Init { dry_run } => {
             // Just run initialization commands, don't actually lint.
@@ -225,6 +231,7 @@ fn do_main() -> Result<i32> {
                 args.output,
                 enable_spinners,
                 revision_opt,
+                args.tee_json,
             )
         }
         SubCommand::Lint => {
@@ -237,6 +244,7 @@ fn do_main() -> Result<i32> {
                 args.output,
                 enable_spinners,
                 revision_opt,
+                args.tee_json,
             )
         }
         SubCommand::Rage { invocation } => do_rage(&persistent_data_store, invocation),

tests/integration_test.rs

@@ -1,6 +1,6 @@
 use anyhow::Result;
 use assert_cmd::Command;
-use insta::assert_yaml_snapshot;
+use insta::{assert_yaml_snapshot, assert_snapshot};
 use lintrunner::lint_message::{LintMessage, LintSeverity};
 use regex::Regex;
 use serde_json;
@@ -666,3 +666,40 @@ fn rage_command_basic() -> Result<()> {
     cmd.assert().success();
     Ok(())
 }
+
+#[test]
+fn tee_json() -> Result<()> {
+    let data_path = tempfile::tempdir()?;
+    let lint_message = LintMessage {
+        path: Some("tests/fixtures/fake_source_file.rs".to_string()),
+        line: Some(9),
+        char: Some(1),
+        code: "DUMMY".to_string(),
+        name: "dummy failure".to_string(),
+        severity: LintSeverity::Advice,
+        original: None,
+        replacement: None,
+        description: Some("A dummy linter failure".to_string()),
+    };
+    let config = temp_config_returning_msg(lint_message)?;
+
+    let mut cmd = Command::cargo_bin("lintrunner")?;
+    cmd.arg(format!("--config={}", config.path().to_str().unwrap()));
+    cmd.arg(format!(
+        "--data-path={}",
+        data_path.path().to_str().unwrap()
+    ));
+    cmd.arg(format!(
+        "--tee-json={}",
+        data_path.path().join("foo.json").display()
+    ));
+    // Run on a file to ensure that the linter is run.
+    cmd.arg("README.md");
+    cmd.assert().failure();
+
+    let tee_json = std::fs::read_to_string(data_path.path().join("foo.json"))?;
+
+    assert_snapshot!("tee_json", tee_json);
+
+    Ok(())
+}

tests/snapshots/integration_test__tee_json.snap

@@ -0,0 +1,6 @@
+---
+source: tests/integration_test.rs
+expression: tee_json
+---
+{"path":"tests/fixtures/fake_source_file.rs","line":9,"char":1,"code":"DUMMY","severity":"advice","name":"dummy failure","description":"A dummy linter failure"}
+