Close #13 save bad rows to a file

src/main.rs

@@ -99,6 +99,10 @@ struct Opt {
     /// quoting.
     #[structopt(value_name = "CHAR", long = "quote", default_value = "\"")]
     quote: CharSpecifier,
+
+    /// Save badly formed rows to a file.
+    #[structopt(value_name = "PATH", long = "bad-rows-path")]
+    bad_rows_path: Option<PathBuf>,
 }
 
 lazy_static! {
@@ -182,6 +186,13 @@ fn run() -> Result<()> {
         .buffer_capacity(BUFFER_SIZE)
         .from_writer(output);
 
+    // Create out CSV writer for bad rows if it is requested.
+    let mut bad_rows_wtr = if let Some(ref path) = opt.bad_rows_path {
+        Some(csv::WriterBuilder::new().from_path(path)?)
+    } else {
+        None
+    };
+
     // Get our header and, if we were asked, make sure all the column names are unique.
     let mut hdr = rdr
         .byte_headers()
@@ -244,6 +255,11 @@ fn run() -> Result<()> {
         // Check if we have the right number of columns in this row.
         if record.len() != expected_cols {
             bad_rows += 1;
+            if let Some(ref mut wtr_bad) = bad_rows_wtr {
+                wtr_bad
+                    .write_record(record.into_iter())
+                    .context("cannot write record")?;
+            };
             continue 'next_row;
         }
 
@@ -303,6 +319,11 @@ fn run() -> Result<()> {
                     // If the column is NULL but shouldn't be, bail on this row.
                     if is_required_col && value.is_empty() {
                         bad_rows += 1;
+                        if let Some(ref mut wtr_bad) = bad_rows_wtr {
+                            wtr_bad
+                                .write_record(record.into_iter())
+                                .context("cannot write record")?;
+                        };
                         continue 'next_row;
                     }
                 }

tests/tests.rs

@@ -111,6 +111,26 @@ fn bad_rows() {
     assert!(output.stderr_str().contains("102 rows (1 bad)"));
 }
 
+#[test]
+fn bad_rows_saved() {
+    let mut good_rows = "a,b,c\n".to_owned();
+    for _ in 0..100 {
+        good_rows.push_str("1,2,3\n");
+    }
+    let mut bad_rows = good_rows.clone();
+    bad_rows.push_str("1,2\n");
+
+    let testdir = TestDir::new("scrubcsv", "bad_rows_saved");
+    let output = testdir
+        .cmd()
+        .args(&["--bad-rows-path", "bad.csv"])
+        .output_with_stdin(&bad_rows)
+        .expect_success();
+    testdir.expect_file_contents("bad.csv", "1,2\n");
+    assert_eq!(output.stdout_str(), &good_rows);
+    assert!(output.stderr_str().contains("102 rows (1 bad)"));
+}
+
 #[test]
 fn too_many_bad_rows() {
     let testdir = TestDir::new("scrubcsv", "too_many_bad_rows");
@@ -200,3 +220,30 @@ a,b,c
 "#
     );
 }
+
+#[test]
+fn drop_row_if_null_saved() {
+    let testdir = TestDir::new("scrubcsv", "drop_row_if_null_saved");
+    let output = testdir
+        .cmd()
+        .arg("--drop-row-if-null=c1")
+        .arg("--drop-row-if-null=c2")
+        .args(&["--bad-rows-path", "bad.csv"])
+        .output_with_stdin(
+            r#"c1,c2,c3
+1,,
+a,b,c
+1,2,3
+3,2,1
+1,4,5
+2,2,2
+1,1,1
+5,5,5
+2,2,2
+1,1,1
+"#,
+        )
+        .expect("error running scrubcsv");
+    eprintln!("{}", output.stderr_str());
+    testdir.expect_file_contents("bad.csv", "1,,\n");
+}