correctly treat backslash in datafusion-cli

Author: Lordworms

datafusion-cli/src/helper.rs

@@ -170,28 +170,38 @@ impl Helper for CliHelper {}
 ///
 /// The data read from stdio will be escaped, so we need to unescape the input before executing the input
 pub fn unescape_input(input: &str) -> datafusion::error::Result<String> {
-    let mut chars = input.chars();
-
+    let mut chars = input.chars().peekable();
     let mut result = String::with_capacity(input.len());
-    while let Some(char) = chars.next() {
-        if char == '\\' {
-            if let Some(next_char) = chars.next() {
-                // https://static.rust-lang.org/doc/master/reference.html#literals
-                result.push(match next_char {
-                    '0' => '\0',
-                    'n' => '\n',
-                    'r' => '\r',
-                    't' => '\t',
-                    '\\' => '\\',
-                    _ => {
-                        return Err(sql_datafusion_err!(ParserError::TokenizerError(
-                            format!("unsupported escape char: '\\{}'", next_char)
-                        )))
+
+    while let Some(ch) = chars.next() {
+        if ch == '\\' {
+            if let Some(&next) = chars.peek() {
+                match next {
+                    '0' => {
+                        chars.next();
+                        result.push('\0');
+                    }
+                    'n' => {
+                        chars.next();
+                        result.push('\n');
                     }
-                });
+                    'r' => {
+                        chars.next();
+                        result.push('\r');
+                    }
+                    't' => {
+                        chars.next();
+                        result.push('\t');
+                    }
+                    _ => result.push('\\'),
+                }
+            } else {
+                return Err(sql_datafusion_err!(ParserError::TokenizerError(
+                    "incomplete escape sequence: trailing backslash".to_string()
+                )));
             }
         } else {
-            result.push(char);
+            result.push(ch);
         }
     }
 

datafusion-cli/tests/cli_integration.rs

@@ -39,6 +39,10 @@ fn init() {
     ["--command", "select 1; select 2;", "--format", "json", "-q"],
     "[{\"Int64(1)\":1}]\n[{\"Int64(2)\":2}]\n"
 )]
+#[case::exec_backslash(
+    ["--file", "tests/data/backslash.txt", "--format", "json", "-q"],
+    "[{\"Utf8(\\\"\\\\\\\")\":\"\\\\\",\"Utf8(\\\"\\\\\\\\\\\")\":\"\\\\\\\\\",\"Utf8(\\\"\\\\\\\\\\\\\\\\\\\\\\\")\":\"\\\\\\\\\\\\\\\\\\\\\",\"Utf8(\\\"\\\\\\\\\\\\\\\\dsdsds\\\\\\\\\\\\\\\")\":\"\\\\\\\\\\\\\\\\dsdsds\\\\\\\\\\\\\",\"Utf8(\\\"\\t\\\")\":\"\\t\",\"Utf8(\\\"\\u0000\\\")\":\"\\u0000\",\"Utf8(\\\"\\n\\\")\":\"\\n\"}]\n"
+)]
 #[case::exec_from_files(
     ["--file", "tests/data/sql.txt", "--format", "json", "-q"],
     "[{\"Int64(1)\":1}]\n"

datafusion-cli/tests/data/backslash.txt

@@ -0,0 +1 @@
+select '\', '\\', '\\\\\', '\\\\dsdsds\\\', '\t', '\0', '\n';