diff --git a/ci/base-tests.sh b/ci/base-tests.sh
index 13b652c0f7d..f7c3342fe38 100755
--- a/ci/base-tests.sh
+++ b/ci/base-tests.sh
@@ -7,6 +7,7 @@ remark -f *.md > /dev/null
 # build clippy in debug mode and run tests
 cargo build --features debugging
 cargo test --features debugging
+cd clippy_lints && cargo test && cd ..
 mkdir -p ~/rust/cargo/bin
 cp target/debug/cargo-clippy ~/rust/cargo/bin/cargo-clippy
 cp target/debug/clippy-driver ~/rust/cargo/bin/clippy-driver
diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs
index ff189d6e893..cf3ea0414da 100644
--- a/clippy_lints/src/consts.rs
+++ b/clippy_lints/src/consts.rs
@@ -16,22 +16,6 @@ use syntax::ast::{FloatTy, LitKind};
 use syntax::ptr::P;
 use crate::utils::{sext, unsext, clip};
 
-#[derive(Debug, Copy, Clone)]
-pub enum FloatWidth {
-    F32,
-    F64,
-    Any,
-}
-
-impl From<FloatTy> for FloatWidth {
-    fn from(ty: FloatTy) -> Self {
-        match ty {
-            FloatTy::F32 => FloatWidth::F32,
-            FloatTy::F64 => FloatWidth::F64,
-        }
-    }
-}
-
 /// A `LitKind`-like enum to fold constant `Expr`s into.
 #[derive(Debug, Clone)]
 pub enum Constant {
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 7d429ce4923..8c03689df43 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -48,9 +48,9 @@ macro_rules! declare_clippy_lint {
     };
 }
 
-pub mod consts;
+mod consts;
 #[macro_use]
-pub mod utils;
+mod utils;
 
 // begin lints modules, do not remove this comment, it’s used in `update_lints`
 pub mod approx_const;
diff --git a/clippy_lints/src/utils/camel_case.rs b/clippy_lints/src/utils/camel_case.rs
new file mode 100644
index 00000000000..e8a8d510fe5
--- /dev/null
+++ b/clippy_lints/src/utils/camel_case.rs
@@ -0,0 +1,114 @@
+/// Return the index of the character after the first camel-case component of
+/// `s`.
+pub fn camel_case_until(s: &str) -> usize {
+    let mut iter = s.char_indices();
+    if let Some((_, first)) = iter.next() {
+        if !first.is_uppercase() {
+            return 0;
+        }
+    } else {
+        return 0;
+    }
+    let mut up = true;
+    let mut last_i = 0;
+    for (i, c) in iter {
+        if up {
+            if c.is_lowercase() {
+                up = false;
+            } else {
+                return last_i;
+            }
+        } else if c.is_uppercase() {
+            up = true;
+            last_i = i;
+        } else if !c.is_lowercase() {
+            return i;
+        }
+    }
+    if up {
+        last_i
+    } else {
+        s.len()
+    }
+}
+
+/// Return index of the last camel-case component of `s`.
+pub fn camel_case_from(s: &str) -> usize {
+    let mut iter = s.char_indices().rev();
+    if let Some((_, first)) = iter.next() {
+        if !first.is_lowercase() {
+            return s.len();
+        }
+    } else {
+        return s.len();
+    }
+    let mut down = true;
+    let mut last_i = s.len();
+    for (i, c) in iter {
+        if down {
+            if c.is_uppercase() {
+                down = false;
+                last_i = i;
+            } else if !c.is_lowercase() {
+                return last_i;
+            }
+        } else if c.is_lowercase() {
+            down = true;
+        } else {
+            return last_i;
+        }
+    }
+    last_i
+}
+
+#[cfg(test)]
+mod test {
+    use super::{camel_case_from, camel_case_until};
+
+    #[test]
+    fn from_full() {
+        assert_eq!(camel_case_from("AbcDef"), 0);
+        assert_eq!(camel_case_from("Abc"), 0);
+    }
+
+    #[test]
+    fn from_partial() {
+        assert_eq!(camel_case_from("abcDef"), 3);
+        assert_eq!(camel_case_from("aDbc"), 1);
+    }
+
+    #[test]
+    fn from_not() {
+        assert_eq!(camel_case_from("AbcDef_"), 7);
+        assert_eq!(camel_case_from("AbcDD"), 5);
+    }
+
+    #[test]
+    fn from_caps() {
+        assert_eq!(camel_case_from("ABCD"), 4);
+    }
+
+    #[test]
+    fn until_full() {
+        assert_eq!(camel_case_until("AbcDef"), 6);
+        assert_eq!(camel_case_until("Abc"), 3);
+    }
+
+    #[test]
+    fn until_not() {
+        assert_eq!(camel_case_until("abcDef"), 0);
+        assert_eq!(camel_case_until("aDbc"), 0);
+    }
+
+    #[test]
+    fn until_partial() {
+        assert_eq!(camel_case_until("AbcDef_"), 6);
+        assert_eq!(camel_case_until("CallTypeC"), 8);
+        assert_eq!(camel_case_until("AbcDD"), 3);
+    }
+
+    #[test]
+    fn until_caps() {
+        assert_eq!(camel_case_until("ABCD"), 0);
+    }
+}
\ No newline at end of file
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 1567bd9ffb6..f910080c229 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -38,17 +38,6 @@ pub enum Error {
     Io(io::Error),
     /// Not valid toml or doesn't fit the expected conf format
     Toml(String),
-    /// Type error.
-    Type(
-        /// The name of the key.
-        &'static str,
-        /// The expected type.
-        &'static str,
-        /// The type we got instead.
-        &'static str,
-    ),
-    /// There is an unknown key is the file.
-    UnknownKey(String),
 }
 
 impl fmt::Display for Error {
@@ -56,10 +45,6 @@ impl fmt::Display for Error {
         match *self {
             Error::Io(ref err) => err.fmt(f),
             Error::Toml(ref err) => err.fmt(f),
-            Error::Type(key, expected, got) => {
-                write!(f, "`{}` is expected to be a `{}` but is a `{}`", key, expected, got)
-            },
-            Error::UnknownKey(ref key) => write!(f, "unknown key `{}`", key),
         }
     }
 }
diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
index 976161a40a9..650ea373d97 100644
--- a/clippy_lints/src/utils/mod.rs
+++ b/clippy_lints/src/utils/mod.rs
@@ -21,9 +21,11 @@ use syntax::ast::{self, LitKind};
 use syntax::attr;
 use syntax::source_map::{Span, DUMMY_SP};
 use syntax::errors::DiagnosticBuilder;
-use syntax::ptr::P;
 use syntax::symbol::keywords;
 
+mod camel_case;
+pub use self::camel_case::{camel_case_from, camel_case_until};
+
 pub mod comparisons;
 pub mod conf;
 pub mod constants;
@@ -37,8 +39,6 @@ pub mod ptr;
 pub mod usage;
 pub use self::hir_utils::{SpanlessEq, SpanlessHash};
 
-pub type MethodArgs = HirVec<P<Expr>>;
-
 pub mod higher;
 
 /// Returns true if the two spans come from differing expansions (i.e. one is
@@ -106,17 +106,6 @@ pub fn match_type(cx: &LateContext<'_, '_>, ty: Ty<'_>, path: &[&str]) -> bool {
     }
 }
 
-/// Check if the method call given in `expr` belongs to given type.
-pub fn match_impl_method(cx: &LateContext<'_, '_>, expr: &Expr, path: &[&str]) -> bool {
-    let method_call = cx.tables.type_dependent_defs()[expr.hir_id];
-    let trt_id = cx.tcx.impl_of_method(method_call.def_id());
-    if let Some(trt_id) = trt_id {
-        match_def_path(cx.tcx, trt_id, path)
-    } else {
-        false
-    }
-}
-
 /// Check if the method call given in `expr` belongs to given trait.
 pub fn match_trait_method(cx: &LateContext<'_, '_>, expr: &Expr, path: &[&str]) -> bool {
     let method_call = cx.tables.type_dependent_defs()[expr.hir_id];
@@ -755,69 +744,6 @@ pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> {
     }
 }
 
-/// Return the index of the character after the first camel-case component of
-/// `s`.
-pub fn camel_case_until(s: &str) -> usize {
-    let mut iter = s.char_indices();
-    if let Some((_, first)) = iter.next() {
-        if !first.is_uppercase() {
-            return 0;
-        }
-    } else {
-        return 0;
-    }
-    let mut up = true;
-    let mut last_i = 0;
-    for (i, c) in iter {
-        if up {
-            if c.is_lowercase() {
-                up = false;
-            } else {
-                return last_i;
-            }
-        } else if c.is_uppercase() {
-            up = true;
-            last_i = i;
-        } else if !c.is_lowercase() {
-            return i;
-        }
-    }
-    if up {
-        last_i
-    } else {
-        s.len()
-    }
-}
-
-/// Return index of the last camel-case component of `s`.
-pub fn camel_case_from(s: &str) -> usize {
-    let mut iter = s.char_indices().rev();
-    if let Some((_, first)) = iter.next() {
-        if !first.is_lowercase() {
-            return s.len();
-        }
-    } else {
-        return s.len();
-    }
-    let mut down = true;
-    let mut last_i = s.len();
-    for (i, c) in iter {
-        if down {
-            if c.is_uppercase() {
-                down = false;
-                last_i = i;
-            } else if !c.is_lowercase() {
-                return last_i;
-            }
-        } else if c.is_lowercase() {
-            down = true;
-        } else {
-            return last_i;
-        }
-    }
-    last_i
-}
-
 /// Convenience function to get the return type of a function
 pub fn return_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, fn_item: NodeId) -> Ty<'tcx> {
     let fn_def_id = cx.tcx.hir.local_def_id(fn_item);
@@ -1109,3 +1035,84 @@ pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_, '_, '_>, node: NodeId
     }
     false
 }
+
+#[cfg(test)]
+mod test {
+    use super::{trim_multiline, without_block_comments};
+
+    #[test]
+    fn test_trim_multiline_single_line() {
+        assert_eq!("", trim_multiline("".into(), false));
+        assert_eq!("...", trim_multiline("...".into(), false));
+        assert_eq!("...", trim_multiline("    ...".into(), false));
+        assert_eq!("...", trim_multiline("\t...".into(), false));
+        assert_eq!("...", trim_multiline("\t\t...".into(), false));
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn test_trim_multiline_block() {
+        assert_eq!("\
+    if x {
+        y
+    } else {
+        z
+    }", trim_multiline("    if x {
+            y
+        } else {
+            z
+        }".into(), false));
+        assert_eq!("\
+    if x {
+    \ty
+    } else {
+    \tz
+    }", trim_multiline("    if x {
+        \ty
+        } else {
+        \tz
+        }".into(), false));
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn test_trim_multiline_empty_line() {
+        assert_eq!("\
+    if x {
+        y
+
+    } else {
+        z
+    }", trim_multiline("    if x {
+            y
+
+        } else {
+            z
+        }".into(), false));
+    }
+
+    #[test]
+    fn test_without_block_comments_lines_without_block_comments() {
+        let result = without_block_comments(vec!["/*", "", "*/"]);
+        println!("result: {:?}", result);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
+        assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
+
+        let result = without_block_comments(vec!["/* rust", "", "*/"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* one-line comment */"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["foo", "bar", "baz"]);
+        assert_eq!(result, vec!["foo", "bar", "baz"]);
+    }
+}
\ No newline at end of file
diff --git a/clippy_lints/src/utils/paths.rs b/clippy_lints/src/utils/paths.rs
index 4d89f8ddffb..3c03645cc1b 100644
--- a/clippy_lints/src/utils/paths.rs
+++ b/clippy_lints/src/utils/paths.rs
@@ -9,8 +9,6 @@ pub const BEGIN_PANIC: [&str; 3] = ["std", "panicking", "begin_panic"];
 pub const BEGIN_PANIC_FMT: [&str; 3] = ["std", "panicking", "begin_panic_fmt"];
 pub const BINARY_HEAP: [&str; 4] = ["alloc", "collections", "binary_heap", "BinaryHeap"];
 pub const BORROW_TRAIT: [&str; 3] = ["core", "borrow", "Borrow"];
-pub const BOX: [&str; 3] = ["std", "boxed", "Box"];
-pub const BOX_NEW: [&str; 4] = ["std", "boxed", "Box", "new"];
 pub const BTREEMAP: [&str; 5] = ["alloc", "collections", "btree", "map", "BTreeMap"];
 pub const BTREEMAP_ENTRY: [&str; 5] = ["alloc", "collections", "btree", "map", "Entry"];
 pub const BTREESET: [&str; 5] = ["alloc", "collections", "btree", "set", "BTreeSet"];
@@ -22,16 +20,13 @@ pub const COW: [&str; 3] = ["alloc", "borrow", "Cow"];
 pub const CSTRING_NEW: [&str; 5] = ["std", "ffi", "c_str", "CString", "new"];
 pub const C_VOID: [&str; 4] = ["std", "os", "raw", "c_void"];
 pub const C_VOID_LIBC: [&str; 2] = ["libc", "c_void"];
-pub const DEBUG_FMT_METHOD: [&str; 4] = ["core", "fmt", "Debug", "fmt"];
 pub const DEFAULT_TRAIT: [&str; 3] = ["core", "default", "Default"];
 pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];
 pub const DISPLAY_FMT_METHOD: [&str; 4] = ["core", "fmt", "Display", "fmt"];
 pub const DOUBLE_ENDED_ITERATOR: [&str; 4] = ["core", "iter", "traits", "DoubleEndedIterator"];
 pub const DROP: [&str; 3] = ["core", "mem", "drop"];
 pub const DURATION: [&str; 3] = ["core", "time", "Duration"];
-pub const FMT_ARGUMENTS_NEWV1: [&str; 4] = ["core", "fmt", "Arguments", "new_v1"];
 pub const FMT_ARGUMENTS_NEWV1FORMATTED: [&str; 4] = ["core", "fmt", "Arguments", "new_v1_formatted"];
-pub const FMT_ARGUMENTV1_NEW: [&str; 4] = ["core", "fmt", "ArgumentV1", "new"];
 pub const FROM_FROM: [&str; 4] = ["core", "convert", "From", "from"];
 pub const FROM_TRAIT: [&str; 3] = ["core", "convert", "From"];
 pub const HASH: [&str; 2] = ["hash", "Hash"];
@@ -43,7 +38,6 @@ pub const INDEX_MUT: [&str; 3] = ["core", "ops", "IndexMut"];
 pub const INIT: [&str; 4] = ["core", "intrinsics", "", "init"];
 pub const INTO: [&str; 3] = ["core", "convert", "Into"];
 pub const INTO_ITERATOR: [&str; 4] = ["core", "iter", "traits", "IntoIterator"];
-pub const IO_PRINT: [&str; 4] = ["std", "io", "stdio", "_print"];
 pub const IO_READ: [&str; 3] = ["std", "io", "Read"];
 pub const IO_WRITE: [&str; 3] = ["std", "io", "Write"];
 pub const ITERATOR: [&str; 4] = ["core", "iter", "iterator", "Iterator"];
@@ -69,9 +63,7 @@ pub const RANGE_FROM: [&str; 3] = ["core", "ops", "RangeFrom"];
 pub const RANGE_FROM_STD: [&str; 3] = ["std", "ops", "RangeFrom"];
 pub const RANGE_FULL: [&str; 3] = ["core", "ops", "RangeFull"];
 pub const RANGE_FULL_STD: [&str; 3] = ["std", "ops", "RangeFull"];
-pub const RANGE_INCLUSIVE: [&str; 3] = ["core", "ops", "RangeInclusive"];
 pub const RANGE_INCLUSIVE_NEW: [&str; 4] = ["core", "ops", "RangeInclusive", "new"];
-pub const RANGE_INCLUSIVE_STD: [&str; 3] = ["std", "ops", "RangeInclusive"];
 pub const RANGE_INCLUSIVE_STD_NEW: [&str; 4] = ["std", "ops", "RangeInclusive", "new"];
 pub const RANGE_STD: [&str; 3] = ["std", "ops", "Range"];
 pub const RANGE_TO: [&str; 3] = ["core", "ops", "RangeTo"];
@@ -81,7 +73,6 @@ pub const RANGE_TO_STD: [&str; 3] = ["std", "ops", "RangeTo"];
 pub const RC: [&str; 3] = ["alloc", "rc", "Rc"];
 pub const REGEX: [&str; 3] = ["regex", "re_unicode", "Regex"];
 pub const REGEX_BUILDER_NEW: [&str; 5] = ["regex", "re_builder", "unicode", "RegexBuilder", "new"];
-pub const REGEX_BYTES: [&str; 3] = ["regex", "re_bytes", "Regex"];
 pub const REGEX_BYTES_BUILDER_NEW: [&str; 5] = ["regex", "re_builder", "bytes", "RegexBuilder", "new"];
 pub const REGEX_BYTES_NEW: [&str; 4] = ["regex", "re_bytes", "Regex", "new"];
 pub const REGEX_BYTES_SET_NEW: [&str; 5] = ["regex", "re_set", "bytes", "RegexSet", "new"];
diff --git a/clippy_lints/src/utils/sugg.rs b/clippy_lints/src/utils/sugg.rs
index 3d587a72eec..8b1b8a31ac2 100644
--- a/clippy_lints/src/utils/sugg.rs
+++ b/clippy_lints/src/utils/sugg.rs
@@ -177,6 +177,7 @@ impl<'a> Sugg<'a> {
 
     /// Convenience method to create the `<lhs>..<rhs>` or `<lhs>...<rhs>`
     /// suggestion.
+    #[allow(dead_code)]
     pub fn range(self, end: &Self, limit: ast::RangeLimits) -> Sugg<'static> {
         match limit {
             ast::RangeLimits::HalfOpen => make_assoc(AssocOp::DotDot, &self, end),
diff --git a/tests/camel_case.rs b/tests/camel_case.rs
deleted file mode 100644
index b7efbde6596..00000000000
--- a/tests/camel_case.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-extern crate clippy_lints;
-
-use clippy_lints::utils::{camel_case_from, camel_case_until};
-
-#[test]
-fn from_full() {
-    assert_eq!(camel_case_from("AbcDef"), 0);
-    assert_eq!(camel_case_from("Abc"), 0);
-}
-
-#[test]
-fn from_partial() {
-    assert_eq!(camel_case_from("abcDef"), 3);
-    assert_eq!(camel_case_from("aDbc"), 1);
-}
-
-#[test]
-fn from_not() {
-    assert_eq!(camel_case_from("AbcDef_"), 7);
-    assert_eq!(camel_case_from("AbcDD"), 5);
-}
-
-#[test]
-fn from_caps() {
-    assert_eq!(camel_case_from("ABCD"), 4);
-}
-
-#[test]
-fn until_full() {
-    assert_eq!(camel_case_until("AbcDef"), 6);
-    assert_eq!(camel_case_until("Abc"), 3);
-}
-
-#[test]
-fn until_not() {
-    assert_eq!(camel_case_until("abcDef"), 0);
-    assert_eq!(camel_case_until("aDbc"), 0);
-}
-
-#[test]
-fn until_partial() {
-    assert_eq!(camel_case_until("AbcDef_"), 6);
-    assert_eq!(camel_case_until("CallTypeC"), 8);
-    assert_eq!(camel_case_until("AbcDD"), 3);
-}
-
-#[test]
-fn until_caps() {
-    assert_eq!(camel_case_until("ABCD"), 0);
-}
diff --git a/tests/trim_multiline.rs b/tests/trim_multiline.rs
deleted file mode 100644
index a0db2e59a29..00000000000
--- a/tests/trim_multiline.rs
+++ /dev/null
@@ -1,57 +0,0 @@
-
-
-/// test the multiline-trim function
-extern crate clippy_lints;
-
-use clippy_lints::utils::trim_multiline;
-
-#[test]
-fn test_single_line() {
-    assert_eq!("", trim_multiline("".into(), false));
-    assert_eq!("...", trim_multiline("...".into(), false));
-    assert_eq!("...", trim_multiline("    ...".into(), false));
-    assert_eq!("...", trim_multiline("\t...".into(), false));
-    assert_eq!("...", trim_multiline("\t\t...".into(), false));
-}
-
-#[test]
-#[rustfmt::skip]
-fn test_block() {
-    assert_eq!("\
-if x {
-    y
-} else {
-    z
-}", trim_multiline("    if x {
-        y
-    } else {
-        z
-    }".into(), false));
-    assert_eq!("\
-if x {
-\ty
-} else {
-\tz
-}", trim_multiline("    if x {
-    \ty
-    } else {
-    \tz
-    }".into(), false));
-}
-
-#[test]
-#[rustfmt::skip]
-fn test_empty_line() {
-    assert_eq!("\
-if x {
-    y
-
-} else {
-    z
-}", trim_multiline("    if x {
-        y
-
-    } else {
-        z
-    }".into(), false));
-}
diff --git a/tests/without_block_comments.rs b/tests/without_block_comments.rs
deleted file mode 100644
index 730c5cb128f..00000000000
--- a/tests/without_block_comments.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-extern crate clippy_lints;
-use clippy_lints::utils::without_block_comments;
-
-#[test]
-fn test_lines_without_block_comments() {
-    let result = without_block_comments(vec!["/*", "", "*/"]);
-    println!("result: {:?}", result);
-    assert!(result.is_empty());
-
-    let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
-    assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
-
-    let result = without_block_comments(vec!["/* rust", "", "*/"]);
-    assert!(result.is_empty());
-
-    let result = without_block_comments(vec!["/* one-line comment */"]);
-    assert!(result.is_empty());
-
-    let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
-    assert!(result.is_empty());
-
-    let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
-    assert!(result.is_empty());
-
-    let result = without_block_comments(vec!["foo", "bar", "baz"]);
-    assert_eq!(result, vec!["foo", "bar", "baz"]);
-}