Add conditional `if` expressions to runtime configuration by Copilot · Pull Request #16638 · github/gh-aw

Copilot · 2026-02-18T20:30:52Z

Centrally-defined workflows using workflow_call cannot provide runtime configuration at compile time. This adds support for GitHub Actions conditional expressions in the runtimes section to enable file-based runtime detection.

Changes

Runtime Configuration

Added optional if field to RuntimeConfig accepting GitHub Actions expressions
Propagated IfCondition through RuntimeRequirement to step generation
Updated runtimesConfigToMap to preserve if field in round-trip conversion

Compilation Pipeline

Modified generateSetupStep to emit if: condition in generated YAML
Updated applyRuntimeOverrides to extract and apply conditional expressions
Schema updated to validate if property in runtime objects

Testing

Unit tests for parsing, conversion, and step generation
Integration test for end-to-end workflow compilation with conditionals

Example

runtimes:
  go:
    version: "1.25"
    if: hashFiles('go.mod') != ''
  python:
    version: "3.11"
    if: hashFiles('requirements.txt') != '' || hashFiles('pyproject.toml') != ''

Generates:

- name: Setup Go
  uses: actions/setup-go@<sha>
  if: hashFiles('go.mod') != ''
  with:
    go-version: '1.25'

Supports full GitHub Actions expression syntax. Backward compatible - runtimes without if conditions unchanged.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

https://api.github.com/graphql
- Triggering command: /usr/bin/gh /usr/bin/gh api graphql -f query=query($owner: String!, $name: String!) { repository(owner: $owner, name: $name) { hasDiscussionsEnabled } } -f owner=github -f name=gh-aw GOMOD GOMODCACHE go env ck 'scripts/**/*GOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh /usr/bin/gh api graphql -f query=query($owner: String!, $name: String!) { repository(owner: $owner, name: $name) { hasDiscussionsEnabled } } -f owner=github -f name=gh-aw GOMOD GOMODCACHE go m/_n�� -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh /usr/bin/gh api graphql -f query=query($owner: String!, $name: String!) { repository(owner: $owner, name: $name) { hasDiscussionsEnabled } } -f owner=github -f name=gh-aw GOMOD GOMODCACHE go env GOPATH); \ if coGOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
https://api.github.com/repos/actions/checkout/git/ref/tags/11bd71901bbe5b1630ceea73d27597364c9af683
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/11bd71901bbe5b1630ceea73d27597364c9af683 --jq .object.sha -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE node /hom�� --check **/*.cjs 64/bin/go **/*.json --ignore-path ../../../.pretti/home/REDACTED/work/gh-aw/gh-aw/.github/workflows go (http block)
https://api.github.com/repos/actions/checkout/git/ref/tags/v6
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v6 --jq .object.sha xFkv/UoPwMwqRq6HGOSUMDB GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE 0313489/b375/imprev-parse -c che/go-build/a2/a2615bb3240425a6GOINSECURE GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f (http block)
https://api.github.com/repos/actions/github-script/git/ref/tags/v7
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v7 --jq .object.sha -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE ache/go/1.25.0/xGO111MODULE env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v7 --jq .object.sha -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE erignore env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v7 --jq .object.sha che/go-build/f9/f9dd00c75c79c7baGOINSECURE GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p github.com/githu-1 -lang=go1.25 go (http block)
https://api.github.com/repos/actions/setup-go/git/ref/tags/4dc6199c7b1a012772edbd06daecab0f50c9053c
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/4dc6199c7b1a012772edbd06daecab0f50c9053c --jq .object.sha k/gh-aw/gh-aw/pkg/stringutil/ideGOINSECURE k/gh-aw/gh-aw/pkg/stringutil/patGOMOD 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse -o /tmp/go-build3940313489/b395/_pkGOINSECURE -trimpath 64/bin/go -p main -lang=go1.25 go (http block)
https://api.github.com/repos/actions/setup-go/git/ref/tags/v5
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/v5 --jq .object.sha -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE node (http block)
https://api.github.com/repos/actions/setup-go/git/ref/tags/v6
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/v6 --jq .object.sha GOSUMDB GOWORK 64/bin/go GOINSECURE GOMOD GOMODCACHE go env ck 'scripts/**/*GOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/v6 --jq .object.sha g/styles/theme.gGOINSECURE g/styles/theme_tGOMOD 64/bin/go GOINSECURE GOMOD GOMODCACHE ache/go/1.25.0/xGO111MODULE env 0313489/b326/_pkGOINSECURE GO111MODULE 64/bin/go GOINSECURE b/gh-aw/pkg/work--norc GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/v6 --jq .object.sha 35126d5394e2a1caGOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE ache/go/1.25.0/xGO111MODULE env 0313489/b398/_pkGOINSECURE GO111MODULE 64/bin/go GOINSECURE b/gh-aw/pkg/test--norc GOMODCACHE go (http block)
https://api.github.com/repos/actions/setup-node/git/ref/tags/v6
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-node/git/ref/tags/v6 --jq .object.sha GOSUMDB GOWORK 64/bin/go GOINSECURE GOMOD GOMODCACHE go env ck 'scripts/**/*GOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-node/git/ref/tags/v6 --jq .object.sha g/stringutil/ideGOINSECURE g/stringutil/patGOMOD 64/bin/go GOINSECURE GOMOD GOMODCACHE ache/go/1.25.0/xGO111MODULE env 0313489/b395/_pkGOINSECURE GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-node/git/ref/tags/v6 --jq .object.sha "prettier" --check 'scripts/**/*GOINSECURE GOPROXY 9bc83b2626bd1c50ffc60cd633225807-d GOSUMDB GOWORK 64/bin/go go env -json GO111MODULE x_amd64/vet GOINSECURE GOMOD GOMODCACHE x_amd64/vet (http block)
https://api.github.com/repos/anchore/sbom-action/git/ref/tags/v0
- Triggering command: /usr/bin/gh gh api /repos/anchore/sbom-action/git/ref/tags/v0 --jq .object.sha che/go-build/b7/remote.origin.url GOPROXY $name) { hasDiscussionsEnabled } } GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p github.com/githu-C -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/anchore/sbom-action/git/ref/tags/v0 --jq .object.sha k/gh-aw/gh-aw/pkremote.origin.url k/gh-aw/gh-aw/pkg/repoutil/repouGOMOD 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse -o /tmp/go-build3940313489/b391/_pkGOINSECURE -trimpath 64/bin/go -p main -lang=go1.25 go (http block)
https://api.github.com/repos/docker/build-push-action/git/ref/tags/v6
- Triggering command: /usr/bin/gh gh api /repos/docker/build-push-action/git/ref/tags/v6 --jq .object.sha che/go-build/12/12f9de6d07e84c14GOINSECURE GOPROXY $name) { hasDiscussionsEnabled } } GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse -o /tmp/go-build3940313489/b382/_pkGOINSECURE -trimpath 64/bin/go -p github.com/githu-1 -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/docker/build-push-action/git/ref/tags/v6 --jq .object.sha k/gh-aw/gh-aw/pkg/styles/theme.gGOINSECURE k/gh-aw/gh-aw/pkg/styles/theme_tGOMOD $name) { hasDiscussionsEnabled } } GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p github.com/githu-1 -lang=go1.25 go (http block)
https://api.github.com/repos/docker/login-action/git/ref/tags/v3
- Triggering command: /usr/bin/gh gh api /repos/docker/login-action/git/ref/tags/v3 --jq .object.sha che/go-build/28/2888c116b4dd41c7GOINSECURE GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse -o /tmp/go-build3940313489/b383/_pkGOINSECURE -trimpath 64/bin/go -p github.com/githu-1 -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/docker/login-action/git/ref/tags/v3 --jq .object.sha che/go-build/35/35126d5394e2a1caGOINSECURE GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse -o /tmp/go-build3940313489/b398/_pkGOINSECURE -trimpath 64/bin/go -p github.com/githu-C -lang=go1.25 go (http block)
https://api.github.com/repos/docker/metadata-action/git/ref/tags/v5
- Triggering command: /usr/bin/gh gh api /repos/docker/metadata-action/git/ref/tags/v5 --jq .object.sha 0313489/b387/embremote.origin.url GOPROXY 64/bin/go GOSUMDB GOWORK run-script/lib/ngraphql /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p main -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/docker/metadata-action/git/ref/tags/v5 --jq .object.sha k/gh-aw/gh-aw/pkg/sliceutil/slicGOINSECURE k/gh-aw/gh-aw/pkg/sliceutil/slicGOMOD 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p main -lang=go1.25 go (http block)
https://api.github.com/repos/docker/setup-buildx-action/git/ref/tags/v3
- Triggering command: /usr/bin/gh gh api /repos/docker/setup-buildx-action/git/ref/tags/v3 --jq .object.sha 0313489/b374/embedcfg GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc-f -o /tmp/go-build394-f -trimpath 64/bin/go -p github.com/githu-C -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/docker/setup-buildx-action/git/ref/tags/v3 --jq .object.sha che/go-build/b1/-f GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolcrev-parse @/tm�� x_amd64/vet git 64/bin/go -v origin 64/bin/go go (http block)
https://api.github.com/repos/github/gh-aw/git/ref/tags/c4e091835c7a94dc7d3acb8ed3ae145afb4995f3
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/c4e091835c7a94dc7d3acb8ed3ae145afb4995f3 --jq .object.sha tformat GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE sh (http block)
https://api.github.com/repos/githubnext/agentics/git/ref/tags/-
- Triggering command: /usr/bin/gh gh api /repos/githubnext/agentics/git/ref/tags/- --jq .object.sha -json GO111MODULE $name) { hasDiscussionsEnabled } } GOINSECURE GOMOD GOMODCACHE go env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE node (http block)
https://api.github.com/user
- Triggering command: /usr/bin/gh gh api user --jq .login d -n 10 (http block)
- Triggering command: /usr/bin/gh gh api user --jq .login rt/yaml/yaml_default.go (http block)
- Triggering command: /usr/bin/gh gh api user --jq .login (http block)

If you need me to access, download, or install something from one of these locations, you can either:

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Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

This section details on the original issue you should resolve

<issue_title>Automatically detect runtimes to install based on files in the repository</issue_title>
<issue_description>Current behavior: runtime (go, python, uv) setup is driven by runtimes: and/or detection; steps run whenever that runtime is selected. Detection is done by parsing the custom steps for commands to create runtimes from.

In my use-case im centrally defining workflows that are workflow_call-ed. In this case a user can't provide the runtime keys they need nor can they provide steps that can be detected at compile time.

It would be nice if runtimes could contain an if conditional that could default (or at least be used) to detecting the presence of certain well known files like install the go runtime if go.mod exists, install the uv runtime if uv.lock exists, etc.
</issue_description>

Comments on the Issue (you are @copilot in this section)
@pelikhan do you have some simple code samples? @pelikhan @copilot update `runtimes` to specify a custom `if` condition that gets merged in the generated steps.

Fixes Automatically detect runtimes to install based on files in the repository #16615

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Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot

Pull request overview

This PR adds conditional execution support for runtime setup steps in GitHub Actions workflows by introducing an optional if field to runtime configurations. This enables file-based runtime detection, which is particularly useful for centrally-defined workflows using workflow_call that cannot provide runtime configuration at compile time.

Changes:

Added if field to RuntimeConfig and RuntimeRequirement structures to accept GitHub Actions conditional expressions
Modified step generation to emit if: conditions in the generated YAML when specified
Updated schema validation to accept the new if property in runtime objects

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pkg/workflow/frontmatter_types.go	Added `If` field to `RuntimeConfig` struct and updated parsing/conversion logic to handle optional `if` conditions
pkg/workflow/runtime_definitions.go	Added `IfCondition` field to `RuntimeRequirement` struct
pkg/workflow/runtime_overrides.go	Modified to extract and apply `if` conditions from runtime configuration
pkg/workflow/runtime_step_generator.go	Updated step generation to emit `if:` condition in YAML when present
pkg/parser/schemas/main_workflow_schema.json	Added schema validation for the new `if` property with description and examples
pkg/workflow/frontmatter_types_test.go	Added comprehensive unit tests for parsing and round-trip conversion of runtime configs with `if` conditions
pkg/workflow/runtime_setup_test.go	Added tests for step generation with various `if` conditions across different runtimes
pkg/workflow/runtime_integration_test.go	Added end-to-end integration tests validating the full compilation pipeline with conditional expressions

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Copilot · 2026-02-18T21:46:50Z

pkg/workflow/runtime_step_generator.go

 		fmt.Sprintf("        uses: %s", actionRef),
 	}

+	// Add if condition if specified
+	if req.IfCondition != "" {
+		step = append(step, fmt.Sprintf("        if: %s", req.IfCondition))
+	}
+


The if: condition is inserted after the uses: line but before the with: block. According to GitHub Actions YAML syntax, the if: condition should appear immediately after the step name and before uses:. The current placement may work but violates the conventional order of step properties (name, if, uses, with, run, etc.).

Suggested change

fmt.Sprintf(" uses: %s", actionRef),

}

// Add if condition if specified

if req.IfCondition != "" {

step = append(step, fmt.Sprintf(" if: %s", req.IfCondition))

}

}

// Add if condition if specified (must appear before 'uses:' in the step)

if req.IfCondition != "" {

step = append(step, fmt.Sprintf(" if: %s", req.IfCondition))

}

// Add the action reference after any 'if:' condition

step = append(step, fmt.Sprintf(" uses: %s", actionRef))

Copilot · 2026-02-18T21:46:51Z

pkg/workflow/frontmatter_types.go

+		// Extract version (optional)
+		var version string
+		if versionAny, hasVersion := configMap["version"]; hasVersion {


The comment "Extract version (optional)" is misleading. While the version field itself is optional in the YAML, the changed logic now allows runtime configs with only an if condition and no version. Consider updating the comment to clarify that a runtime config can have either a version, an if condition, or both.

Copilot · 2026-02-18T21:46:51Z

pkg/workflow/frontmatter_types.go

+		nodeMap := map[string]any{}
+		if config.Node.Version != "" {
+			nodeMap["version"] = config.Node.Version
+		}
+		if config.Node.If != "" {
+			nodeMap["if"] = config.Node.If
+		}
+		if len(nodeMap) > 0 {
+			result["node"] = nodeMap
+		}


The conversion logic for each runtime (node, python, go, uv, bun, deno) is duplicated six times with only the runtime name and config field changing. This repetitive code could be refactored into a helper function that takes the runtime name and config as parameters, reducing code duplication and making future modifications easier.

Initial plan

5ad8d14

Copilot AI assigned Copilot and pelikhan Feb 18, 2026

Copilot started work on behalf of pelikhan February 18, 2026 20:30 View session

Copilot AI and others added 2 commits February 18, 2026 20:40

Add custom if conditions support for runtimes configuration

d00e690

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Complete implementation and validation of runtime if conditions

878da22

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Add automatic runtime detection based on repository files~~ Add conditional if expressions to runtime configuration Feb 18, 2026

Copilot finished work on behalf of pelikhan February 18, 2026 20:46

pelikhan marked this pull request as ready for review February 18, 2026 21:44

Copilot AI review requested due to automatic review settings February 18, 2026 21:44

pelikhan merged commit 41df3c3 into main Feb 18, 2026
128 checks passed

pelikhan deleted the copilot/automatically-detect-runtimes branch February 18, 2026 21:45

Copilot started reviewing on behalf of pelikhan February 18, 2026 21:45 View session

Copilot AI reviewed Feb 18, 2026

View reviewed changes

github-actions bot mentioned this pull request Feb 19, 2026

[instructions] Sync github-agentic-workflows.md with v0.46.1 #16675

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Add conditional `if` expressions to runtime configuration#16638

Add conditional `if` expressions to runtime configuration#16638
pelikhan merged 3 commits intomainfrom
copilot/automatically-detect-runtimes

Copilot AI commented Feb 18, 2026 •

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Changes

Runtime Configuration

Compilation Pipeline

Testing

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Copilot AI commented Feb 18, 2026 •

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