feat: add `joinEnv` and `joinUrl` string functions and 2 new system vars by solvingj · Pull Request #2408 · go-task/task

solvingj · 2025-09-03T02:44:28Z

Add two new system variables which map directly to platform specific go constants:

PATH_LIST_SEPARATOR -> os.PathListSeparator
FILE_PATH_SEPARATOR -> os.PathSeparator

Add joinEnv string function which is sibling to joinPath:

strings.Join(elem, string(os.PathListSeparator))

Add joinUrl string function which is sibling to joinPath:

path.Join(elem...)

Add all to docs

closes #2406

trulede

@solvingj there are quite a few functions already in https://go-task.github.io/slim-sprig/ and perhaps its better to use those existing list functions (join, append, prepend) since that gives a better control over how such lists/strings are generated.

The PathSeparator and PathListSeparator are useful however I would suggest following the existing most-predominate naming convention:

PathSeparator -> osPathSeparator (note also the absence of "file")
PathListSeparator -> osPathListSeparator

since the allcaps just looks ODD.

Observation: this could also be done with a .env file, introducing these constants (and others). Perhaps this PR is more effort than value.

solvingj · 2025-09-13T03:21:41Z

Up to @pd93 and @andreynering I suppose.

vmaerten

Hello!
Sorry for the delay, we have been busy lately.

PATH_LIST_SEPARATOR / FILE_PATH_SEPARATOR does not work in the templating system.

If you take this Taskfile :

# https://taskfile.dev

version: '3'

tasks:
  default:
    cmds:
      - echo "{{.PATH_LIST_SEPARATOR}}"
      - echo "{{.FILE_PATH_SEPARATOR}}"

You will get this result:

For these variables, you need to define them in getSpecialVars inside compiler.go

solvingj · 2025-11-05T14:54:57Z

For these variables, you need to define them in getSpecialVars inside compiler.go

Ah, of course, moved...

vmaerten · 2025-12-12T21:23:39Z

@solvingj the lint is failing. Do you still want to work on it?

solvingj · 2025-12-20T00:51:57Z

Yah I can fix it tomorrow. Just to confirm, are you sure you want to merge it?

solvingj · 2026-02-17T14:40:50Z

@vmaerten i just added this proposed example to the ENV_PRECEDENCE documentation:
d5431e0

Just pointing out that the use case would be a touch more elegant with this feature.

trulede · 2026-03-14T21:32:07Z

 	return true
 }

+func joinEnv(elem ...string) string {


Why is this called joinEnv? It has nothing to do with environment.

There is already a join function in slim-sprig which takes a second argument for the separator. Would this not be more suitable, along with the added seperator (in this PR).

Why is this called joinEnv? It has nothing to do with environment.

os.PathListSeparator is abstract rune which resolves to the character ":" when compiled on posix operating systems, and ";" on windows. It represents the special value used by these operating systems when parsing 1 or more filesystem paths from an environment variable, such as in the special case of PATH.

This function returns a string, which is the combination of input strings, but with the appropriate platform-specific character placed in-between each. In this way, it returns a string which is valid to be assigned to an environment variable which is designated to hold 1 or more filesystem paths.

Thus, this function is related to environment variables, and that is why it was called joinEnv.

I apologize for not explaining this more clearly in the original description.

trulede · 2026-03-14T21:44:08Z

+}
+
+func joinUrl(elem ...string) string {
+	return path.Join(elem...)


There is already a joinPath function. Any reason not to use that? It calls filepath.Join.

Also, there is an existing urlJoin which is actually joining a URL. And a corresponding urlParse. Those are both working with URLs, the function presented here is not...

There is already a joinPath function. Any reason not to use that? It calls filepath.Join.

filepath.Join is abstract method which takes 1 or more strings understood to be filesystem paths, and combines them by putting the platform-specific separator in-between each element. When compiled on posix operating systems, the separator used is "/", when compiled on windows, the separator is "\".

When joining path elements for a URL, the inputs must be combined together, with the character "/" placed in-between each element. The path.Join function does this. The use of joinPath on posix operating-systems returns a valid URL with the "/" character, however when called on windows with the same inputs, the function returns a string with the separator "\" placed in-between each element. This result is not a valid URL.

This is one of two key reason why this function is implemented, and why it used the path.Join function instead of filepath.Join.

Also, there is an existing urlJoin which is actually joining a URL. And a corresponding urlParse. Those are both working with URLs, the function presented here is not...

urlJoin is a function which takes an input of type map and combines them into a URL based on a number of optional inputs, according to RFC 3986. It looks for the following keys (with example values provided):

scheme: 'http' host: 'server.com:8080' path: '/api' query: 'list=false' opaque: nil fragment: 'anchor' userinfo: 'admin:secret'

The path key supports a single string value. If the path of the url has multiple path elements, such as api,foo, and bar, they must be combined into a single string prior to calling this function. To be valid, they must be combined with the "/" character in-between each element, such as /api/foo/bar.

This is the second of the two key reason why this function is implemented. It provides a first-class way to prepare a path string for use with URLs, including for use with the existing urlJoin function.

I apologize for not explaining these things more clearly in the original description.

trulede · 2026-03-14T22:03:39Z

@solvingj why not just add pathJoinList alongside the existing pathJoin? And don't bother will all the additional stuff.

For your problem, its much neater than dealing with the separators. It seems like it would just solve your problem (sorry I don't exactly know the templating syntax to use here, but you will get the point):

export PATH={{pathJoinList env PWD/tools/bin env PATH}}

https://github.com/SergioChan/task/blob/54bdcba369357b47e19066b57badfb216a4c8d95/internal/templater/funcs.go#L35

solvingj · 2026-03-19T02:32:57Z

@solvingj why not just add pathJoinList alongside the existing pathJoin? And don't bother will all the additional stuff.

For your problem, its much neater than dealing with the separators. It seems like it would just solve your problem (sorry I don't exactly know the templating syntax to use here, but you will get the point):

export PATH={{pathJoinList env PWD/tools/bin env PATH}}

https://github.com/SergioChan/task/blob/54bdcba369357b47e19066b57badfb216a4c8d95/internal/templater/funcs.go#L35

This suggested implementation does not result in the desired behavior (it does not pass the included unit tests). To try to help understand why, I have provided some responses to your other comments and questions in this PR, with some key details about how the functions you mentioned work. Your confusion is understandable, as the details of these functions are somewhat esoteric, and cross-platform nuances are often not well-understood. I apologize I did not give more detailed explanations in my original PR description.

andreynering · 2026-04-12T01:33:25Z

Hi @solvingj,

Looks like this build is broken. This needs a rebase.

…constants: - PATH_LIST_SEPARATOR -> os.PathListSeparator - FILE_PATH_SEPARATOR -> os.PathSeparator Add joinEnv string function which is sibling to joinPath: - strings.Join(elem, string(os.PathListSeparator)) Add joinUrl string function which is sibling to joinPath: - path.Join(elem...) Add all to docs closes go-task#2406

- Rebased on latest main branch (origin/main) - Resolved conflicts in compiler.go: merged filepath.ToSlash() changes with new special variables - Fixed type conversion for os.PathListSeparator and os.PathSeparator (rune to string) - Added PATH_LIST_SEPARATOR and FILE_PATH_SEPARATOR to summary filter to prevent them from appearing in task summaries (consistent with other special variables) - All tests passing including linting

solvingj · 2026-04-20T08:01:24Z

@andreynering done. All tests pass locally now.

solvingj · 2026-05-01T19:20:10Z

@andreynering any additional blockers?

andreynering

Thank you for your patience!

trulede reviewed Sep 11, 2025

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andreynering requested review from andreynering, pd93 and vmaerten November 3, 2025 13:39

vmaerten requested changes Nov 3, 2025

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solvingj force-pushed the add_joinenv branch from 99397a4 to b2e1584 Compare February 4, 2026 14:27

trulede reviewed Mar 14, 2026

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trulede mentioned this pull request Mar 14, 2026

templater: add joinEnv helper for PATH-like vars #2733

Closed

solvingj requested a review from vmaerten March 19, 2026 02:34

solvingj added 5 commits April 20, 2026 03:07

Remove accidental guide.md doc change

e2f10d9

Remove accidental guide.md doc change2

42ed161

Move to compiler.go per feedback from @vmaerten

fd6320a

solvingj force-pushed the add_joinenv branch from b2e1584 to 41b59df Compare April 20, 2026 07:34

trulede mentioned this pull request May 5, 2026

Add templating function 'joinPathList' #2825

Closed

andreynering added 2 commits May 9, 2026 11:14

docs: make some documentation adjustments

e28b1de

Merge branch 'main' into add_joinenv

78090fc

andreynering approved these changes May 9, 2026

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andreynering changed the title ~~Add joinEnv and joinUrl string functions and 2 new system vars~~ feat: add joinEnv and joinUrl string functions and 2 new system vars May 9, 2026

andreynering enabled auto-merge (squash) May 9, 2026 14:18

andreynering merged commit d9e0e04 into go-task:main May 9, 2026
14 of 15 checks passed

andreynering added a commit that referenced this pull request May 9, 2026

docs(changelog): add entry for #2406 #2408

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