From 66a152a0aced2f6390ab0367de69bd90a5cf8509 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bartek=20Iwa=C5=84czuk?= <biwanczuk@gmail.com>
Date: Thu, 7 Nov 2024 00:38:04 +0100
Subject: [PATCH] rework

---
 cli/tools/lint/linter.rs        | 105 +------------------
 cli/tools/lint/minified_file.rs | 172 ++++++++++++++++++++++++++++++++
 cli/tools/lint/mod.rs           |   1 +
 3 files changed, 176 insertions(+), 102 deletions(-)
 create mode 100644 cli/tools/lint/minified_file.rs

diff --git a/cli/tools/lint/linter.rs b/cli/tools/lint/linter.rs
index 1dd1549ecd..165d717d9c 100644
--- a/cli/tools/lint/linter.rs
+++ b/cli/tools/lint/linter.rs
@@ -20,6 +20,7 @@ use deno_lint::linter::LinterOptions;
 use crate::util::fs::atomic_write_file_with_retries;
 use crate::util::fs::specifier_from_file_path;
 
+use super::minified_file;
 use super::rules::FileOrPackageLintRule;
 use super::rules::PackageLintRule;
 use super::ConfiguredRules;
@@ -99,7 +100,8 @@ impl CliLinter {
   ) -> Result<(ParsedSource, Vec<LintDiagnostic>), AnyError> {
     let specifier = specifier_from_file_path(file_path)?;
 
-    if is_minified_file(&source_code) {
+    let metrics = minified_file::analyze_content(&source_code);
+    if metrics.is_likely_minified() {
       bail!(
         "{} appears to be a minified file, skipping linting",
         specifier.as_str()
@@ -266,104 +268,3 @@ fn apply_lint_fixes(
     deno_ast::apply_text_changes(text_info.text_str(), quick_fixes);
   Some(new_text)
 }
-
-pub fn is_minified_file(code: &str) -> bool {
-  const LONG_LINE_THRESHOLD: usize = 250;
-  const WHITESPACE_THRESHOLD: f64 = 0.1;
-
-  let mut whitespace_count = 0;
-  let mut total_len = 0;
-  let mut line_count = 0;
-
-  let is_possibly_minified = code.lines().any(|line| {
-    // Line length over the threshold suggests a minified file.
-    let line_len = line.len();
-    if line_len > LONG_LINE_THRESHOLD {
-      return true;
-    }
-
-    let line = line.trim();
-    // So does a source map url.
-    if line.starts_with("//# sourceMappingURL=") {
-      return true;
-    }
-
-    line_count += 1;
-    // Last ditch effort, keep track of whitespace count.
-    if line_len > 0 {
-      whitespace_count +=
-        line.chars().filter(|c| c.is_ascii_whitespace()).count();
-      total_len += line.len();
-    }
-
-    false
-  });
-
-  if is_possibly_minified {
-    return true;
-  }
-
-  eprintln!(
-    "whitespace count {} total_len {}",
-    whitespace_count, total_len
-  );
-  let whitespace_ratio = whitespace_count as f64 / total_len as f64;
-  eprintln!("whitespace_ration {}", whitespace_ratio);
-  whitespace_ratio < WHITESPACE_THRESHOLD
-}
-
-// Example test module
-#[cfg(test)]
-mod tests {
-  use super::*;
-
-  #[test]
-  fn test_minified_file_col_length() {
-    let minified =
-      "const LOREM_IPSUM = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.`";
-    assert!(is_minified_file(minified));
-  }
-
-  #[test]
-  fn test_minified_file_whitespace() {
-    let minified =
-      "function f(a,b){return a.concat(b)}var x=function(n){return n+1};";
-    assert!(is_minified_file(minified));
-  }
-
-  #[test]
-  fn test_minified_file_sourcemap() {
-    let minified = r#"function f(a, b) { return a.concat(b) }
-var x = function(n) { return n + 1; };
-//# sourceMappingURL=sourcefile.map.js"
-"#;
-    assert!(is_minified_file(minified));
-  }
-
-  #[test]
-  fn test_normal_file() {
-    let normal = r#"
-function concatenateArrays(array1, array2) {
-    return array1.concat(array2);
-}
-
-const incrementNumber = function(number) {
-    return number + 1;
-};"#;
-    assert!(!is_minified_file(normal));
-  }
-
-  #[test]
-  fn test_normal_file_source_map() {
-    let normal = r#"
-function concatenateArrays(array1, array2) {
-    return array1.concat(array2);
-}
-
-const incrementNumber = function(number) {
-    return number + 1;
-};
-//# sourceMappingURL=sourcefile.map.js"#;
-    assert!(!is_minified_file(normal));
-  }
-}
diff --git a/cli/tools/lint/minified_file.rs b/cli/tools/lint/minified_file.rs
new file mode 100644
index 0000000000..c015debd46
--- /dev/null
+++ b/cli/tools/lint/minified_file.rs
@@ -0,0 +1,172 @@
+// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
+
+#[derive(Debug)]
+pub struct FileMetrics {
+  long_lines_count: usize,
+  total_lines: usize,
+  whitespace_ratio: f64,
+  has_license_comment: bool,
+}
+
+impl FileMetrics {
+  #[inline]
+  pub fn is_likely_minified(&self) -> bool {
+    let long_lines_ratio =
+      self.long_lines_count as f64 / self.total_lines as f64;
+
+    (long_lines_ratio > 0.3 || self.whitespace_ratio < 0.05)
+      && !(self.has_license_comment && self.total_lines < 5)
+  }
+}
+
+pub fn analyze_content(content: &str) -> FileMetrics {
+  let mut total_lines = 0;
+  let mut long_lines_count = 0;
+  let mut whitespace_count = 0;
+  let mut total_chars = 0;
+  let mut has_license = false;
+  let mut in_multiline_comment = false;
+
+  // Preallocate a line buffer to avoid per-line allocations
+  let mut line_buffer = String::with_capacity(1024);
+
+  // Process the content character by character to avoid line allocations
+  let mut chars = content.chars().peekable();
+  while let Some(c) = chars.next() {
+    total_chars += 1;
+
+    if c.is_whitespace() {
+      whitespace_count += 1;
+    }
+
+    line_buffer.push(c);
+
+    // Check for end of line or end of content
+    if c == '\n' || chars.peek().is_none() {
+      total_lines += 1;
+      let trimmed = line_buffer.trim();
+
+      // Check for license/copyright only if we haven't found one yet
+      if !has_license && !trimmed.is_empty() {
+        // Avoid allocating a new string for case comparison
+        has_license = trimmed.chars().any(|c| c.is_ascii_alphabetic())
+          && (trimmed.contains("license")
+            || trimmed.contains("LICENSE")
+            || trimmed.contains("copyright")
+            || trimmed.contains("COPYRIGHT")
+            || trimmed.contains("(c)")
+            || trimmed.contains("(C)"));
+      }
+
+      // Handle comments without allocating new strings
+      if trimmed.starts_with("/*") {
+        in_multiline_comment = true;
+      }
+      if trimmed.ends_with("*/") {
+        in_multiline_comment = false;
+        line_buffer.clear();
+        continue;
+      }
+      if in_multiline_comment || trimmed.starts_with("//") {
+        line_buffer.clear();
+        continue;
+      }
+
+      // Check line length
+      if line_buffer.len() > 250 {
+        long_lines_count += 1;
+      }
+
+      line_buffer.clear();
+    }
+  }
+
+  // Handle case where file doesn't end with newline
+  if !line_buffer.is_empty() {
+    total_lines += 1;
+  }
+
+  let whitespace_ratio = if total_chars > 0 {
+    whitespace_count as f64 / total_chars as f64
+  } else {
+    0.0
+  };
+
+  FileMetrics {
+    long_lines_count,
+    total_lines,
+    whitespace_ratio,
+    has_license_comment: has_license,
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_normal_js() {
+    let content = r#"
+function hello() {
+    // This is a normal comment
+    console.log("Hello, world!");
+}
+
+// Another comment
+const x = 42;
+
+/* Multi-line
+    comment */
+"#;
+    let metrics = analyze_content(content);
+    assert!(!metrics.is_likely_minified());
+  }
+
+  #[test]
+  fn test_minified_file_col_length() {
+    let content =
+      "const LOREM_IPSUM = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.`";
+    let metrics = analyze_content(content);
+    assert!(metrics.is_likely_minified());
+  }
+
+  #[test]
+  fn test_minified_js() {
+    let content = "function hello(){console.log(\"Hello, world!\")}const x=42;function veryLongFunction(){return\"This is a very long line that exceeds 250 characters and contains lots of code and stuff and more code and even more stuff until we definitely exceed the limit we set for considering a line to be very long in our minification detection algorithm\"}";
+    let metrics = analyze_content(content);
+    assert!(metrics.is_likely_minified());
+  }
+
+  #[test]
+  fn test_minified_file_whitespace() {
+    let content =
+      "function f(a,b){return a.concat(b)}var x=function(n){return n+1};";
+    let metrics = analyze_content(content);
+    assert!(!metrics.is_likely_minified());
+  }
+
+  #[test]
+  fn test_license_only() {
+    let content = r#"/* 
+* Copyright (c) 2024 Example Corp.
+* Licensed under MIT License
+*/
+"#;
+    let metrics = analyze_content(content);
+    assert!(!metrics.is_likely_minified());
+  }
+
+  #[test]
+  fn test_normal_file() {
+    let content = r#"
+function concatenateArrays(array1, array2) {
+    return array1.concat(array2);
+}
+
+const incrementNumber = function(number) {
+    return number + 1;
+};"#;
+    let metrics = analyze_content(content);
+    assert!(!metrics.is_likely_minified());
+  }
+}
diff --git a/cli/tools/lint/mod.rs b/cli/tools/lint/mod.rs
index e096b486ef..404297117e 100644
--- a/cli/tools/lint/mod.rs
+++ b/cli/tools/lint/mod.rs
@@ -52,6 +52,7 @@ use crate::util::path::is_script_ext;
 use crate::util::sync::AtomicFlag;
 
 mod linter;
+mod minified_file;
 mod reporters;
 mod rules;