Changelog
v5.7.0
- Several compile-time evaluation and inlining fixes
- Allow
reduce_funcs
to be disabled again.
- Add
spidermonkey
options to parse and format (#974)
- Accept
{get = "default val"}
and {set = "default val"}
in destructuring arguments.
- Change package.json export map to help require.resolve (#971)
- Improve docs
- Fix
export default
of an anonymous class with extends
v5.6.1
- Mark assignments to the
.prototype
of a class as pure
- Parenthesize
await
on the left of **
(while accepting legacy non-parenthesised input)
- Avoided outputting NUL bytes in optimized RegExps, to stop the output from breaking other tools
- Added
exports
to domprops (#939)
- Fixed a crash when spreading
...this
- Fixed the computed size of arrow functions, which improves their inlining
v5.6.0
- Added top-level await
- Beautify option has been removed in #895
- Private properties, getters and setters have been added in #913 and some more commits
- Docs improvements: #896, #903, #916
v5.5.1
- Fixed object properties with unicode surrogates on safari.
v5.5.0
- Fixed crash when inlining uninitialized variable into template string.
- The sourcemap for dist was removed for being too large.
v5.4.0
- Logical assignment
- Change
let x = undefined
to just let x
- Removed some optimizations for template strings, placing them behind
unsafe
options. Reason: adding strings is not equivalent to template strings, due to valueOf differences.
- The AST_Token class was slimmed down in order to use less memory.
v5.3.8
v5.3.7
Hotfix release, fixes package.json "engines" syntax
v5.3.6
- Fixed parentheses when outputting
??
mixed with ||
and &&
- Improved hygiene of the symbol generator
v5.3.5
- Avoid moving named functions into default exports.
- Enabled transform() for chain expressions. This allows AST transformers to reach inside chain expressions.
v5.3.4
- Fixed a crash when hoisting (with
hoist_vars
) a destructuring variable declaration
v5.3.3
source-map
library has been updated, bringing memory usage and CPU time improvements when reading input source maps (the SourceMapConsumer is now WASM based).
- The
wrap_func_args
option now also wraps arrow functions, as opposed to only function expressions.
v5.3.2
- Prevented spread operations from being expanded when the expanded array/object contains getters, setters, or array holes.
- Fixed very slow self-recursion in some cases of removing extraneous parentheses from
+
operations.
v5.3.1
- An issue with destructuring declarations when
pure_getters
is enabled has been fixed
- Fixed a crash when chain expressions need to be shallowly compared
- Made inlining functions more conservative to make sure a function that contains a reference to itself isn't moved into a place that can create multiple instances of itself.
v5.3.0
- Fixed a crash when compressing object spreads in some cases
- Fixed compiletime evaluation of optional chains (caused typeof a?.b to always return "object")
- domprops has been updated to contain every single possible prop
v5.2.1
- The parse step now doesn't accept an
ecma
option, so that all ES code is accepted.
- Optional dotted chains now accept keywords, just like dotted expressions (
foo?.default
)
v5.2.0
- Optional chaining syntax is now supported.
- Consecutive await expressions don't have unnecessary parens
- Taking the variable name's length (after mangling) into consideration when deciding to inline
v5.1.0
import.meta
is now supported
- Typescript typings have been improved
v5.0.0
in
operator now taken into account during property mangle.
- Fixed infinite loop in face of a reference loop in some situations.
- Kept exports and imports around even if there's something which will throw before them.
- The main exported bundle for commonjs, dist/bundle.min.js is no longer minified.
v5.0.0-beta.0
- BREAKING:
minify()
is now async and rejects a promise instead of returning an error.
- BREAKING: Internal AST is no longer exposed, so that it can be improved without releasing breaking changes.
- BREAKING: Lowest supported node version is 10
- BREAKING: There are no more warnings being emitted
- Module is now distributed as a dual package - You can
import
and require()
too.
- Inline improvements were made
v4.8.0
- Support for numeric separators (
million = 1_000_000
) was added.
- Assigning properties to a class is now assumed to be pure.
- Fixed bug where
yield
wasn't considered a valid property key in generators.
v4.7.0
- A bug was fixed where an arrow function would have the wrong size
arguments
object is now considered safe to retrieve properties from (useful for length
, or 0
) even when pure_getters
is not set.
- Fixed erroneous
const
declarations without value (which is invalid) in some corner cases when using collapse_vars
.
v4.6.13
- Fixed issue where ES5 object properties were being turned into ES6 object properties due to more lax unicode rules.
- Fixed parsing of BigInt with lowercase
e
in them.
v4.6.12
- Fixed subtree comparison code, making it see that
[1,[2, 3]]
is different from [1, 2, [3]]
- Printing of unicode identifiers has been improved
v4.6.11
- Read unused classes' properties and method keys, to figure out if they use other variables.
- Prevent inlining into block scopes when there are name collisions
- Functions are no longer inlined into parameter defaults, because they live in their own special scope.
- When inlining identity functions, take into account the fact they may be used to drop
this
in function calls.
- Nullish coalescing operator (
x ?? y
), plus basic optimization for it.
- Template literals in binary expressions such as
+
have been further optimized
v4.6.10
- Do not use reduce_vars when classes are present
v4.6.9
- Check if block scopes actually exist in blocks
v4.6.8
- Take into account "executed bits" of classes like static properties or computed keys, when checking if a class evaluation might throw or have side effects.
v4.6.7
- Some new performance gains through a
AST_Node.size()
method which measures a node's source code length without printing it to a string first.
- An issue with setting
--comments
to false
in the CLI has been fixed.
- Fixed some issues with inlining
unsafe_symbols
compress option was added, which turns Symbol("name")
into just Symbol()
- Brought back compress performance improvement through the
AST_Node.equivalent_to(other)
method (which was reverted in v4.6.6).
v4.6.6
(hotfix release)
- Reverted code to 4.6.4 to allow for more time to investigate an issue.
v4.6.5 (REVERTED)
- Improved compress performance through using a new method to see if two nodes are equivalent, instead of printing them to a string.
v4.6.4
- The
"some"
value in the comments
output option now preserves @lic
and other important comments when using //
</script>
is now better escaped in regex, and in comments, when using the inline_script
output option
- Fixed an issue when transforming
new RegExp
into /.../
when slashes are included in the source
AST_Node.prototype.constructor
now exists, allowing for easier debugging of crashes
- Multiple if statements with the same consequents are now collapsed
- Typescript typings improvements
- Optimizations while looking for surrogate pairs in strings
v4.6.3
- Annotations such as
/*#__NOINLINE__*/
and /*#__PURE__*/
may now be preserved using the preserve_annotations
output option
- A TypeScript definition update for the
keep_quoted
output option.
v4.6.2
- A bug where functions were inlined into other functions with scope conflicts has been fixed.
/*#__NOINLINE__*/
annotation fixed for more use cases where inlining happens.
v4.6.1
- Fixed an issue where a class is duplicated by reduce_vars when there's a recursive reference to the class.
v4.6.0
- Fixed issues with recursive class references.
- BigInt evaluation has been prevented, stopping Terser from evaluating BigInts like it would do regular numbers.
- Class property support has been added
v4.5.1
(hotfix release)
- Fixed issue where
() => ({})[something]
was not parenthesised correctly.
v4.5.0
- Inlining has been improved
- An issue where keep_fnames combined with functions declared through variables was causing name shadowing has been fixed
- You can now set the ES version through their year
- The output option
keep_numbers
has been added, which prevents Terser from turning 1000
into 1e3
and such
- Internal small optimisations and refactors
v4.4.3
- Number and BigInt parsing has been fixed
/*#__INLINE__*/
annotation fixed for arrow functions with non-block bodies.
- Functional tests have been added, using this repository.
- A memory leak, where the entire AST lives on after compression, has been plugged.
v4.4.2
- Fixed a problem with inlining identity functions
v4.4.1
note: This introduced a feature, therefore it should have been a minor release.
- Fixed a crash when
unsafe
was enabled.
- An issue has been fixed where
let
statements might be collapsed out of their scope.
- Some error messages have been improved by adding quotes around variable names.
v4.4.0
- Added
/*#__INLINE__*/
and /*#__NOINLINE__*/
annotations for calls. If a call has one of these, it either forces or forbids inlining.
v4.3.11
- Fixed a problem where
window
was considered safe to access, even though there are situations where it isn't (Node.js, workers...)
- Fixed an error where
++
and --
were considered side-effect free
Number(x)
now needs both unsafe
and and unsafe_math
to be compressed into +x
because x
might be a BigInt
keep_fnames
now correctly supports regexes when the function is in a variable declaration
v4.3.10
- Fixed syntax error when repeated semicolons were encountered in classes
- Fixed invalid output caused by the creation of empty sequences internally
- Scopes are now updated when scopes are inlined into them
v4.3.9
- Fixed issue with mangle's
keep_fnames
option, introduced when adding code to keep variable names of anonymous functions
v4.3.8
v4.3.7
- Parsing of regex options in the CLI (which broke in v4.3.5) was fixed.
- typescript definition updates
v4.3.6
(crash hotfix)
v4.3.5
- Fixed an issue with DOS line endings strings separated by
\
and a new line.
- Improved fix for the output size regression related to unused references within the extends section of a class.
- Variable names of anonymous functions (eg:
const x = () => { ... }
or var func = function () {...}
) are now preserved when keep_fnames is true.
- Fixed performance degradation introduced for large payloads in v4.2.0
v4.3.4
- Fixed a regression where the output size was increased when unused classes were referred to in the extends clause of a class.
- Small typescript typings fixes.
- Comments with
@preserve
, @license
, @cc_on
as well as comments starting with /*!
and /**!
are now preserved by default.
v4.3.3
- Fixed a problem where parsing template strings would mix up octal notation and a slash followed by a zero representing a null character.
- Started accepting the name
async
in destructuring arguments with default value.
- Now Terser takes into account side effects inside class
extends
clauses.
- Added parens whenever there's a comment between a return statement and the returned value, to prevent issues with ASI.
- Stopped using raw RegExp objects, since the spec is going to continue to evolve. This ensures Terser is able to process new, unknown RegExp flags and features. This is a breaking change in the AST node AST_RegExp.
v4.3.2
- Typescript typing fix
- Ensure that functions can't be inlined, by reduce_vars, into places where they're accessing variables with the same name, but from somewhere else.
v4.3.1
- Fixed an issue from 4.3.0 where any block scope within a for loop erroneously had its parent set to the function scopee
- Fixed an issue where compressing IIFEs with argument expansions would result in some parameters becoming undefined
- addEventListener options argument's properties are now part of the DOM properties list.
v4.3.0
- Do not drop computed object keys with side effects
- Functions passed to other functions in calls are now wrapped in parentheses by default, which speeds up loading most modules
- Objects with computed properties are now less likely to be hoisted
- Speed and memory efficiency optimizations
- Fixed scoping issues with
try
and switch
v4.2.1
- Minor refactors
- Fixed a bug similar to #369 in collapse_vars
- Functions can no longer be inlined into a place where they're going to be compared with themselves.
- reduce_funcs option is now legacy, as using reduce_vars without reduce_funcs caused some weird corner cases. As a result, it is now implied in reduce_vars and can't be turned off without turning off reduce_vars.
- Bug which would cause a random stack overflow has now been fixed.
v4.2.0
- When the source map URL is
inline
, don't write it to a file.
- Fixed output parens when a lambda literal is the tag on a tagged template string.
- The
mangle.properties.undeclared
option was added. This enables the property mangler to mangle properties of variables which can be found in the name cache, but whose properties are not known to this Terser run.
- The v8 bug where the toString and source representations of regexes like
RegExp("\\\n")
includes an actual newline is now fixed.
- Now we're guaranteed to not have duplicate comments in the output
- Domprops updates
v4.1.4
- Fixed a crash when inlining a function into somewhere else when it has interdependent, non-removable variables.
v4.1.3
- Several issues with the
reduce_vars
option were fixed.
- Starting this version, we only have a dist/bundle.min.js
v4.1.2
v4.1.1
- Fixed a bug where toplevel scopes were being mixed up with lambda scopes
v4.1.0
- Internal functions were replaced by
Object.assign
, Array.prototype.some
, Array.prototype.find
and Array.prototype.every
.
- A serious issue where some ESM-native code was broken was fixed.
- Performance improvements were made.
- Support for BigInt was added.
- Inline efficiency was improved. Functions are now being inlined more proactively instead of being inlined only after another Compressor pass.
v4.0.2
(Hotfix release. Reverts unmapped segments PR #342, which will be put back on Terser when the upstream issue is resolved)
v4.0.1
- Collisions between the arguments of inlined functions and names in the outer scope are now being avoided while inlining
- Unmapped segments are now preserved when compressing a file which has source maps
- Default values of functions are now correctly converted from Mozilla AST to Terser AST
- JSON ⊂ ECMAScript spec (if you don't know what this is you don't need to)
- Export AST_* classes to library users
- Fixed issue with
collapse_vars
when functions are created with the same name as a variable which already exists
- Added
MutationObserverInit
(Object with options for initialising a mutation observer) properties to the DOM property list
- Custom
Error
subclasses are now internally used instead of old-school Error inheritance hacks.
- Documentation fixes
- Performance optimizations
v4.0.0
- breaking change: The
variables
property of all scopes has become a standard JavaScript Map
as opposed to the old bespoke Dictionary
object.
- Typescript definitions were fixed
terser --help
was fixed
- The public interface was cleaned up
- Fixed optimisation of
Array
and new Array
- Added the
keep_quoted=strict
mode to mangle_props, which behaves more like Google Closure Compiler by mangling all unquoted property names, instead of reserving quoted property names automatically.
- Fixed parent functions' parameters being shadowed in some cases
- Allowed Terser to run in a situation where there are custom functions attached to Object.prototype
- And more bug fixes, optimisations and internal changes
v3.17.0
- More DOM properties added to --mangle-properties's DOM property list
- Closed issue where if 2 functions had the same argument name, Terser would not inline them together properly
- Fixed issue with
hasOwnProperty.call
- You can now list files to minify in a Terser config file
- Started replacing
new Array(<number>)
with an array literal
- Started using ES6 capabilities like
Set
and the includes
method for strings and arrays
v3.16.1
- Fixed issue where Terser being imported with
import
would cause it not to work due to the __esModule
property. (PR #254 was submitted, which was nice, but since it wasn't a pure commonJS approach I decided to go with my own solution)
v3.16.0
- No longer leaves names like Array or Object or window as a SimpleStatement (statement which is just a single expression).
- Add support for sections sourcemaps (IndexedSourceMapConsumer)
- Drops node.js v4 and starts using commonJS
- Is now built with rollup
v3.15.0
- Inlined spread syntax (
[...[1, 2, 3], 4, 5] => [1, 2, 3, 4, 5]
) in arrays and objects.
- Fixed typo in compressor warning
- Fixed inline source map input bug
- Fixed parsing of template literals with unnecessary escapes (Like
\\a
)