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Commit7bbe8d4

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Document pointer pattern for path existence checking
Add documentation and tests showing how to use pointer types withDecodePath to check if a path exists rather than relying on zero values.This follows standard Go patterns for optional values.
1 parentdd4a944 commit7bbe8d4

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2 files changed

+25
-1
lines changed

2 files changed

+25
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lines changed

‎reader_test.go‎

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Original file line numberDiff line numberDiff line change
@@ -367,6 +367,16 @@ func TestDecodePath(t *testing.T) {
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varneuint
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require.NoError(t,result.DecodePath(&ne,"does-not-exist",1))
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assert.Equal(t,uint(0),ne)
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// Test pointer pattern for path existence checking
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varexistingStringPtr*string
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require.NoError(t,result.DecodePath(&existingStringPtr,"utf8_string"))
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assert.NotNil(t,existingStringPtr,"existing path should decode to non-nil pointer")
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assert.Equal(t,"unicode! ☯ - ♫",*existingStringPtr)
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varnonExistentStringPtr*string
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require.NoError(t,result.DecodePath(&nonExistentStringPtr,"does-not-exist"))
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assert.Nil(t,nonExistentStringPtr,"non-existent path should decode to nil pointer")
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}
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typeTestInterfaceinterface {

‎result.go‎

Lines changed: 15 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -59,6 +59,20 @@ func (r Result) Decode(v any) error {
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//
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// If the path is empty, the entire data structure is decoded into v.
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//
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// To check if a path exists (rather than relying on zero values), decode
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// into a pointer and check if it remains nil:
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//
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//var city *string
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//err := result.DecodePath(&city, "city", "names", "en")
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//if err != nil {
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//// Handle error
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//}
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//if city == nil {
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//// Path not found
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//} else {
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//// Path exists, city contains the value
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//}
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//
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// Returns an error if:
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// - the path is invalid
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// - the data cannot be decoded into the type of v
@@ -69,7 +83,7 @@ func (r Result) Decode(v any) error {
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// Example usage:
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//
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//var city string
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//err := result.DecodePath(&city, "location", "city", "names", "en")
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//err := result.DecodePath(&city, "city", "names", "en")
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//
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//var geonameID int
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//err := result.DecodePath(&geonameID, "subdivisions", 0, "geoname_id")

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