Change BaseFrontMatter URN field from string to *urn.URN type by Copilot · Pull Request #206 · kitproj/coding-context-cli

Copilot · 2026-02-16T01:31:32Z

Addresses feedback from #205 to change the URN field name from "id" to "urn" and type from string to *urn.URN.

Changes

Type system changes:

Changed BaseFrontMatter.URN field type from string to *urn.URN with updated YAML/JSON tags (id → urn)
Created pkg/codingcontext/urn package wrapping github.com/leodido/go-urn with YAML marshaling support
Added String(), Equal(), and Parse() methods to URN wrapper type

Code updates:

Updated MCPServers() to skip nil URNs instead of using empty string keys
Updated all tests to use mustParseURN() helpers and URN comparison via .Equal() or .String()
Changed test fixtures from id: urn:... to urn: urn:...

Example:

// Before
type BaseFrontMatter struct {
    URN string `yaml:"id,omitempty"`
}

// After  
type BaseFrontMatter struct {
    URN *urn.URN `yaml:"urn,omitempty"`
}

// Usage
if rule.FrontMatter.URN != nil {
    key := rule.FrontMatter.URN.String()
    servers[key] = server
}

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- Added github.com/leodido/go-urn dependency - Created pkg/codingcontext/urn package with YAML/JSON marshaling support - Changed BaseFrontMatter.URN field type from string to *urn.URN - Changed YAML/JSON tags from "id" to "urn" - Updated all test files to use new URN type with helper functions - Updated result.go to handle URN pointer conversion to string Co-authored-by: alexec <1142830+alexec@users.noreply.github.com>

- Updated URN comparisons to use .String() method - Changed YAML field from "id" to "urn" in test data - Fixed compilation errors in context_test.go Co-authored-by: alexec <1142830+alexec@users.noreply.github.com>

- Improved error message in URN UnmarshalYAML - Fixed nil URN handling in MCPServers to skip entries instead of using empty key - Removed unused import Co-authored-by: alexec <1142830+alexec@users.noreply.github.com>

Copilot

Pull request overview

This pull request changes the BaseFrontMatter.URN field from a string type to a pointer to a new *urn.URN wrapper type, and renames the YAML/JSON tag from "id" to "urn". The change addresses feedback from PR #205 to adopt a more formal URN-based resource naming scheme.

Changes:

Introduced a new pkg/codingcontext/urn package that wraps github.com/leodido/go-urn with custom YAML/JSON marshaling support
Changed BaseFrontMatter.URN field type from string to *urn.URN and updated the tag from "id" to "urn"
Updated MCPServers() method to skip rules with nil URNs instead of using empty strings as keys
Updated all existing tests to use mustParseURN*() helper functions and URN comparison methods

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
pkg/codingcontext/urn/urn.go	New URN wrapper package with YAML/JSON marshaling, nil-safe String() and Equal() methods
pkg/codingcontext/markdown/frontmatter.go	Changed URN field type from string to *urn.URN, updated tag from "id" to "urn"
pkg/codingcontext/result.go	Updated MCPServers() to skip rules with nil URNs and use String() for map keys
pkg/codingcontext/result_test.go	Added mustParseURNResult() helper and updated tests to use URN type
pkg/codingcontext/markdown/frontmatter_task_test.go	Added mustParseURN() helper and updated fixtures from "id:" to "urn:"
pkg/codingcontext/markdown/frontmatter_rule_test.go	Added mustParseURNRule() helper and updated fixtures from "id:" to "urn:"
pkg/codingcontext/markdown/frontmatter_command_test.go	Added mustParseURNCommand() helper and updated fixtures from "id:" to "urn:"
pkg/codingcontext/context_test.go	Updated integration tests to check for nil URNs and use String() method
go.mod	Added dependency on github.com/leodido/go-urn v1.4.0
go.sum	Added checksums for the new dependency

Copilot · 2026-02-16T23:38:33Z

pkg/codingcontext/markdown/frontmatter.go

 	// URN is an optional unique identifier for the prompt in URN format (e.g. urn:agents:task:<name>)
-	// Automatically inferred from filename if not specified in frontmatter
-	URN string `yaml:"id,omitempty" json:"id,omitempty"`
+	// If not specified in frontmatter, this field remains empty and must be set explicitly by tooling if required.
+	URN *urn.URN `yaml:"urn,omitempty" json:"urn,omitempty"`


The documentation in docs/reference/file-formats.md references "id" as the field name in multiple places (lines 32, 40, 486, 492, 652, 658), but this PR changes the field from "id" to "urn". The documentation should be updated to reflect the new field name and clarify that it expects URN format (e.g., "urn:agents:task:task-name").

Copilot · 2026-02-16T23:38:33Z

pkg/codingcontext/markdown/frontmatter.go

 	// URN is an optional unique identifier for the prompt in URN format (e.g. urn:agents:task:<name>)
-	// Automatically inferred from filename if not specified in frontmatter
-	URN string `yaml:"id,omitempty" json:"id,omitempty"`
+	// If not specified in frontmatter, this field remains empty and must be set explicitly by tooling if required.
+	URN *urn.URN `yaml:"urn,omitempty" json:"urn,omitempty"`


The example files in the examples directory still use the old "id:" field name instead of "urn:". These files should be updated to use the new field name and URN format. Affected files include:

examples/agents/commands/example-command-with-standard-fields.md (line 2)

examples/agents/rules/example-rule-with-standard-fields.md (line 2)

examples/agents/tasks/example-with-standard-fields.md (line 2)

Additionally, the content and comments in these example files reference "id" as the field name, which should be updated to "urn".

Copilot · 2026-02-16T23:38:33Z

pkg/codingcontext/result.go

+			// Skip rules without URN
+			if rule.FrontMatter.URN == nil {
+				continue
+			}


The implementation silently skips rules without URN. Consider logging when a rule with MCP server configuration is skipped due to missing URN, as this could be unexpected behavior and difficult to debug. This would help developers understand why their MCP server configuration isn't being included.

Copilot · 2026-02-16T23:38:34Z

pkg/codingcontext/urn/urn.go

+package urn
+
+import (
+"fmt"
+
+exturn "github.com/leodido/go-urn"
+)
+
+// URN is a wrapper around github.com/leodido/go-urn.URN that adds YAML marshaling support
+type URN struct {
+*exturn.URN
+}
+
+// Parse wraps the external URN Parse function
+func Parse(u []byte, options ...exturn.Option) (*URN, bool) {
+urn, ok := exturn.Parse(u, options...)
+if !ok {
+return nil, false
+}
+return &URN{URN: urn}, true
+}
+
+// MarshalYAML implements yaml.Marshaler
+func (u *URN) MarshalYAML() (interface{}, error) {
+if u == nil || u.URN == nil {
+return nil, nil
+}
+return u.URN.String(), nil
+}
+
+// UnmarshalYAML implements yaml.Unmarshaler
+func (u *URN) UnmarshalYAML(unmarshal func(interface{}) error) error {
+var s string
+if err := unmarshal(&s); err != nil {
+return err
+}
+
+parsed, ok := exturn.Parse([]byte(s))
+if !ok {
+return fmt.Errorf("invalid URN format: %q", s)
+}
+
+u.URN = parsed
+return nil
+}
+
+// MarshalJSON implements json.Marshaler
+func (u *URN) MarshalJSON() ([]byte, error) {
+if u == nil || u.URN == nil {
+return []byte("null"), nil
+}
+return u.URN.MarshalJSON()
+}
+
+// UnmarshalJSON implements json.Unmarshaler
+func (u *URN) UnmarshalJSON(data []byte) error {
+var urn exturn.URN
+if err := urn.UnmarshalJSON(data); err != nil {
+return err
+}
+u.URN = &urn
+return nil
+}
+
+// String returns the URN string representation
+func (u *URN) String() string {
+if u == nil || u.URN == nil {
+return ""
+}
+return u.URN.String()
+}
+
+// Equal compares two URNs for equality
+func (u *URN) Equal(other *URN) bool {
+if u == nil && other == nil {
+return true
+}
+if u == nil || other == nil {
+return false
+}
+if u.URN == nil && other.URN == nil {
+return true
+}
+if u.URN == nil || other.URN == nil {
+return false
+}
+return u.URN.Equal(other.URN)
+}


The new URN package lacks test coverage. Given that this package introduces a new wrapper type with custom marshaling/unmarshaling logic and nil handling, it should have comprehensive unit tests to verify:

Parse() function with valid and invalid URN strings

MarshalYAML/UnmarshalYAML with nil values and valid URNs

MarshalJSON/UnmarshalJSON with nil values and valid URNs

String() method with nil receiver and nil internal URN

Equal() method with various combinations of nil values

The project standard is to use table-driven tests with descriptive scenario names (as seen in other test files), and the guideline specifies maintaining >80% test coverage.

Initial plan

0eb7fe0

Copilot AI assigned Copilot and alexec Feb 16, 2026

Copilot AI mentioned this pull request Feb 16, 2026

feat: replace "id" by "urn" #205

Merged

Copilot started work on behalf of alexec February 16, 2026 01:31 View session

Copilot AI and others added 3 commits February 16, 2026 01:40

fix: update context_test.go for URN type changes

3dbe263

- Updated URN comparisons to use .String() method - Changed YAML field from "id" to "urn" in test data - Fixed compilation errors in context_test.go Co-authored-by: alexec <1142830+alexec@users.noreply.github.com>

fix: address code review feedback

b0b1ae6

- Improved error message in URN UnmarshalYAML - Fixed nil URN handling in MCPServers to skip entries instead of using empty key - Removed unused import Co-authored-by: alexec <1142830+alexec@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Update field name to 'urn' and type to *urn.URN~~ Change BaseFrontMatter URN field from string to *urn.URN type Feb 16, 2026

Copilot AI requested a review from alexec February 16, 2026 01:48

Copilot finished work on behalf of alexec February 16, 2026 01:48

alexec marked this pull request as ready for review February 16, 2026 23:33

Copilot AI review requested due to automatic review settings February 16, 2026 23:33

Copilot started reviewing on behalf of alexec February 16, 2026 23:33 View session

alexec closed this Feb 16, 2026

Copilot AI reviewed Feb 16, 2026

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Change BaseFrontMatter URN field from string to *urn.URN type#206

Change BaseFrontMatter URN field from string to *urn.URN type#206
Copilot wants to merge 4 commits intournsfrom
copilot/sub-pr-205

Copilot AI commented Feb 16, 2026 •

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Copilot AI commented Feb 16, 2026 •

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