Commit: runtime(handlebars): adds handlebars template syntax & indent support

[Christian Brabandt]

runtime(handlebars): adds handlebars template syntax & indent support

Commit: https://github.com/vim/vim/commit/99ea2b5b062edcb22ac0cd92c5ae317cc663a7ca
Author: Devin Weaver <su...@tritarget.org>
Date: Thu Mar 5 20:06:02 2026 +0000

runtime(handlebars): adds handlebars template syntax & indent support

The runtime had support to detect handlebars (*.hbs) files as filetype
handlebars but was lacking any indent or syntax highlighting for that
filetype.

The handlebars syntax file is also a prerequisite for the glimmer
syntax.

Permission was granted by the original author to retrofit these into the
Vim runtime. Original License (MIT) maintained in code comments.

related: #19569

Signed-off-by: Devin Weaver <su...@tritarget.org>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/.github/MAINTAINERS b/.github/MAINTAINERS
index daf31d7cf..92e9e6025 100644
--- a/.github/MAINTAINERS
+++ b/.github/MAINTAINERS
@@ -388,6 +388,7 @@ runtime/indent/go.vim @dbarnett
runtime/indent/graphql.vim @jparise
runtime/indent/gyp.vim @ObserverOfTime
runtime/indent/haml.vim @tpope
+runtime/indent/handlebars.vim @sukima
runtime/indent/hare.vim @selenebun
runtime/indent/hcl.vim @gpanders
runtime/indent/hog.vim @wtfbbqhax
@@ -551,6 +552,7 @@ runtime/syntax/graphql.vim @jparise
runtime/syntax/groff.vim @jmarshall
runtime/syntax/gyp.vim @ObserverOfTime
runtime/syntax/haml.vim @tpope
+runtime/syntax/handlebars.vim @sukima
runtime/syntax/hare.vim @selenebun
runtime/syntax/haredoc.vim @selenebun
runtime/syntax/haskell.vim @coot
diff --git a/runtime/indent/handlebars.vim b/runtime/indent/handlebars.vim
new file mode 100644
index 000000000..6b76b5a39
--- /dev/null
+++ b/runtime/indent/handlebars.vim
@@ -0,0 +1,128 @@
+" Vim indent file
+" Language: Handlebars
+" Maintainer: Devin Weaver
+" Last Change: 2026 Feb 20
+" Origin: https://github.com/joukevandermaas/vim-ember-hbs
+" Credits: Jouke van der Maas
+" Acknowledgement: Based on eruby.vim indentation by TPope
+" License: MIT
+" The MIT License (MIT)
+"
+" Copyright (c) 2026 Devin Weaver
+" Copyright (c) 2015 Jouke van der Maas
+"
+" Permission is hereby granted, free of charge, to any person obtaining a copy
+" of this software and associated documentation files (the "Software"), to deal
+" in the Software without restriction, including without limitation the rights
+" to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+" copies of the Software, and to permit persons to whom the Software is
+" furnished to do so, subject to the following conditions:
+"
+" The above copyright notice and this permission notice shall be included in all
+" copies or substantial portions of the Software.
+"
+" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+" IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+" FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+" AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+" LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+" OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+" SOFTWARE.
+
+if exists("b:did_indent")
+ finish
+endif
+
+runtime! indent/html.vim
+unlet! b:did_indent
+
+" Force HTML indent to not keep state.
+let b:html_indent_usestate = 0
+let b:handlebars_current_indent = 0
+
+if &l:indentexpr == ''
+ if &l:cindent
+ let &l:indentexpr = 'cindent(v:lnum)'
+ else
+ let &l:indentexpr = 'indent(prevnonblank(v:lnum-1))'
+ endif
+endif
+let b:handlebars_subtype_indentexpr = &l:indentexpr
+
+let b:did_indent = 1
+
+setlocal indentexpr=GetHandlebarsIndent()
+setlocal indentkeys=o,O,*<Return>,<>>,{,},0),0],o,O,!^F,=else,={{#,={{/
+
+" Only define the function once.
+if exists("*GetHandlebarsIndent")
+ finish
+endif
+
+function! GetHandlebarsIndent(...)
+ " The value of a single shift-width
+ let sw = shiftwidth()
+
+ if a:0 && a:1 == '.'
+ let v:lnum = line('.')
+ elseif a:0 && a:1 =~ '^\d'
+ let v:lnum = a:1
+ endif
+ let vcol = col('.')
+ call cursor(v:lnum,1)
+ call cursor(v:lnum,vcol)
+ exe "let ind = ".b:handlebars_subtype_indentexpr
+
+ " Workaround for Andy Wokula's HTML indent. This should be removed after
+ " some time, since the newest version is fixed in a different way. Credit
+ " to eruby.vim indent by tpope
+ if b:handlebars_subtype_indentexpr =~# '^HtmlIndent('
+ \ && exists('b:indent')
+ \ && type(b:indent) == type({})
+ \ && has_key(b:indent, 'lnum')
+ " Force HTML indent to not keep state
+ let b:indent.lnum = -1
+ endif
+
+ let lnum = prevnonblank(v:lnum-1)
+ let prevLine = getline(lnum)
+ let currentLine = getline(v:lnum)
+
+ " all indent rules only apply if the block opening/closing
+ " tag is on a separate line
+
+ " indent after block {{#block
+ if prevLine =~# ' \s*\{\{\#'
+ let ind = ind + sw
+ endif
+ " but not if the block ends on the same line
+ if prevLine =~# ' \s*\{\{\#(.+)(\s+|\}\}).+\{\{\/ '
+ let ind = ind - sw
+ endif
+ " unindent after block close {{/block}}
+ if currentLine =~# ' ^\s*\{\{\/'
+ let ind = ind - sw
+ endif
+ " indent after component block {{a-component
+ if prevLine =~# ' \s*\{\{\w'
+ let ind = ind + sw
+ endif
+ " but not if the component block ends on the same line
+ if prevLine =~# ' \s*\{\{\w(.+)\}\}'
+ let ind = ind - sw
+ endif
+ " unindent }} lines
+ if currentLine =~# ' ^\s*\}\}\s*$' || (currentLine !~# ' ^\s*\{\{\/' && prevLine =~# ' ^\s*[^\{\}]+\}\}\s*$')
+ let ind = ind - sw
+ endif
+ " unindent {{else}}
+ if currentLine =~# ' ^\s*\{\{else'
+ let ind = ind - sw
+ endif
+ " indent again after {{else}}
+ if prevLine =~# ' ^\s*\{\{else'
+ let ind = ind + sw
+ endif
+
+ return ind
+endfunction
diff --git a/runtime/syntax/handlebars.vim b/runtime/syntax/handlebars.vim
new file mode 100644
index 000000000..439a2284f
--- /dev/null
+++ b/runtime/syntax/handlebars.vim
@@ -0,0 +1,144 @@
+" Vim syntax file
+" Language: Handlebars
+" Maintainer: Devin Weaver
+" Last Change: 2026 Feb 20
+" Origin: https://github.com/joukevandermaas/vim-ember-hbs
+" Credits: Jouke van der Maas
+" License: MIT
+" The MIT License (MIT)
+"
+" Copyright (c) 2026 Devin Weaver
+" Copyright (c) 2015 Jouke van der Maas
+"
+" Permission is hereby granted, free of charge, to any person obtaining a copy
+" of this software and associated documentation files (the "Software"), to deal
+" in the Software without restriction, including without limitation the rights
+" to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+" copies of the Software, and to permit persons to whom the Software is
+" furnished to do so, subject to the following conditions:
+"
+" The above copyright notice and this permission notice shall be included in all
+" copies or substantial portions of the Software.
+"
+" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+" IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+" FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+" AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+" LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+" OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+" SOFTWARE.
+
+if exists("b:current_syntax")
+ finish
+endif
+
+runtime! syntax/html.vim
+syntax cluster htmlPreproc add=hbsComponent,hbsMustache,hbsUnescaped,hbsMustacheBlock,hbsComment,hbsElseBlock,hbsEscapedMustache
+
+syntax match hbsEscapedMustache " \\{\{"
+
+syntax region hbsComponent matchgroup=hbsComponentStatement start=" \<\/?:? +(\. +|::-? +)*" end=" \/?\>" keepend
+syntax region hbsMustache matchgroup=hbsHandles start=" \{\{" skip=" \\}\}" end=" \}\}" containedin=hbsComponent,hbsString keepend
+syntax region hbsMustacheBlock matchgroup=hbsHandles start=" \{\{[#/]" skip=" \\}\}" end=" \}\}" keepend
+" modern hbs supports {{else <block>}} where <block> starts a new block
+syntax region hbsElseBlock matchgroup=hbsHandles start=" \{\{else\ "rs=e-5 skip=" \\}\}" end=" \}\}" keepend
+
+syntax region hbsPencil matchgroup=hbsOperator start=" \(" end=" \)" contained containedin=hbsMustache,hbsMustacheBlock,hbsElseBlock,hbsPencil
+
+" identifier is any word inside a mustache or a pencil that is not followed by a = sign (see hbsArg below)
+syntax match hbsIdentifier " (\(|\{\{[#/]?)@<!<(\w+)|(\@\w+)>" contained containedin=hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock,hbsStatement
+
+" unescaped are special forms of mustaches that don't have other stuff except for an identifier in it
+syntax region hbsUnescaped matchgroup=hbsUnescapedHandles start=" \{\{\{" skip=" \\}\}\}" end=" \}\}\}" keepend
+syntax match hbsUnescapedIdentifier " (\{\{\{)@<=<\S+>(\}\}\})" contained containedin=hbsUnescaped
+
+syntax match hbsMustacheName " (\{\{[#/]?)@<=<\S+>" contained containedin=hbsMustache,hbsMustacheBlock,hbsPencil
+syntax match hbsPencilName " (\()@<=<\S+>" contained containedin=hbsMustache,hbsMustacheBlock,hbsPencil
+syntax match hbsBuiltInHelper " \(@<=<(query-params|mut|fn|array|hash|get|action|unbound|concat)>" contained containedin=hbsPencil
+syntax match hbsBuiltInHelper " (\{\{)@<=<(textarea|mut|fn|array|hash|input|get|action|on|input|unbound)>" contained containedin=hbsMustache
+syntax match hbsBuiltInHelper " (\{\{[#/]?)@<=<(component|with|link\-to)>" contained containedin=hbsMustacheBlock,hbsElseBlock
+syntax match hbsBuiltInHelperInElse " (\{\{else\ )@<=<(component|link\-to)>" contained containedin=hbsMustacheBlock,hbsElseBlock
+syntax match hbsControlFlow " (\{\{)@<=<else>( ?)@=" contained containedin=hbsElseBlock
+syntax match hbsControlFlow " \(@<=<(if|unless)>" contained containedin=hbsPencil
+syntax match hbsControlFlow " (\{\{)@<=<(debugger|unless|yield|outlet|else)>" contained containedin=hbsMustache
+syntax match hbsControlFlow " (\{\{[#/]?)@<=<(with|let|if|each(\-in)?|unless)>" contained containedin=hbsMustacheBlock,hbsElseBlock
+syntax match hbsKeyword " \s+as\s+" contained containedin=hbsComponent,hbsMustacheBlock,hbsElseBlock
+syntax region hbsStatement matchgroup=hbsDelimiter start=" \|" end=" \|" contained containedin=hbsComponent,hbsMustacheBlock,hbsElseBlock
+
+syntax region hbsString matchgroup=hbsString start=/ \"/ skip=/ \\"/ end=/ \"/ extend contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+syntax region hbsString matchgroup=hbsString start=/ \'/ skip=/ \\'/ end=/ \'/ extend contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+syntax match hbsNumber " <\d+>" contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+syntax match hbsBool " <(true|false)>" contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+syntax match hbsArg " (\@\S+|\S+)\=@=" contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+syntax match hbsOperator " (\S+)@<=\=" contained containedin=hbsComponent,hbsMustache,hbsMustacheBlock,hbsPencil,hbsElseBlock
+
+syntax region hbsComment start=" \{\{\!" end=" \}\}" keepend
+syntax region hbsComment start=" \{\{\!\-\-" end=" \-\-\}\}" keepend
+
+" *Comment any comment
+
+" *Constant any constant
+" String a string constant: "this is a string"
+" Character a character constant: 'c', '
'
+" Number a number constant: 234, 0xff
+" Boolean a boolean constant: TRUE, false
+" Float a floating point constant: 2.3e10
+
+" *Identifier any variable name
+" Function function name (also: methods for classes)
+
+" *Statement any statement
+" Conditional if, then, else, endif, switch, etc.
+" Repeat for, do, while, etc.
+" Label case, default, etc.
+" Operator "sizeof", "+", "*", etc.
+" Keyword any other keyword
+" Exception try, catch, throw
+
+" *PreProc generic Preprocessor
+" Include preprocessor #include
+" Define preprocessor #define
+" Macro same as Define
+" PreCondit preprocessor #if, #else, #endif, etc.
+
+" *Type int, long, char, etc.
+" StorageClass static, register, volatile, etc.
+" Structure struct, union, enum, etc.
+" Typedef A typedef
+
+" *Special any special symbol
+" SpecialChar special character in a constant
+" Tag you can use CTRL-] on this
+" Delimiter character that needs attention
+" SpecialComment special things inside a comment
+" Debug debugging statements
+
+" *Underlined text that stands out, HTML links
+
+" *Ignore left blank, hidden |hl-Ignore|
+
+" *Error any erroneous construct
+
+" *Todo anything that needs extra attention; mostly the
+" keywords TODO FIXME and XXX
+
+highlight link hbsBuiltInHelper Function
+highlight link hbsBuiltInHelperInElse Function
+highlight link hbsControlFlow Function
+highlight link hbsKeyword Keyword
+highlight link hbsOperator Operator
+highlight link hbsDelimiter Delimiter
+highlight link hbsMustacheName Statement
+highlight link hbsPencilName Statement
+highlight link hbsIdentifier Identifier
+highlight link hbsString String
+highlight link hbsNumber Special
+highlight link hbsBool Boolean
+highlight link hbsHandles Define
+highlight link hbsComponentStatement Define
+highlight link hbsUnescapedHandles Identifier
+highlight link hbsUnescapedIdentifier Identifier
+highlight link hbsComment Comment
+highlight link hbsArg Type
+
+let b:current_syntax = "handlebars"