Improve formatting of floats.

Signed-off-by: Felix Fontein <[email protected]>

Author: felixfontein

functional-tests/src/lib.rs

@@ -306,7 +306,7 @@ bar: baz
         assert!(
             data == "[the_section]
 int           = 123
-float         = 1.230000
+float         = 1.23
 bool          = true
 date          = 2025-01-02T00:00:00Z
 timestamp     = 2025-01-02T03:04:05Z

stores/ini/store.go

@@ -82,7 +82,12 @@ func (store Store) stripCommentChar(comment string) string {
 func (store Store) valToString(v interface{}) string {
 	switch v := v.(type) {
 	case float64:
-		return strconv.FormatFloat(v, 'f', 6, 64)
+		result := strconv.FormatFloat(v, 'G', -1, 64)
+		// If the result can be confused with an integer, make sure we have at least one decimal digit
+		if !strings.ContainsRune(result, '.') && !strings.ContainsRune(result, 'E') {
+			result = strconv.FormatFloat(v, 'f', 1, 64)
+		}
+		return result
 	case bool:
 		return strconv.FormatBool(v)
 	case time.Time:

stores/ini/store_test.go

@@ -187,11 +187,15 @@ func TestUnmarshalMetadataFromNonSOPSFile(t *testing.T) {
 func TestValToString(t *testing.T) {
 	store := Store{}
 	assert.Equal(t, "1", store.valToString(1))
-	assert.Equal(t, "1.000000", store.valToString(1.0))
-	assert.Equal(t, "-20000000000.000000", store.valToString(-2e10))
-	assert.Equal(t, "0.000000", store.valToString(2e-10))
-	assert.Equal(t, "12345000000000000583883634749019137936624068583482471750845213260941541453980911162485633595979333632.000000", store.valToString(1.2345e100))
-	assert.Equal(t, "0.000000", store.valToString(1.2345e-100))
+	assert.Equal(t, "1.0", store.valToString(1.0))
+	assert.Equal(t, "1.1", store.valToString(1.10))
+	assert.Equal(t, "1.23", store.valToString(1.23))
+	assert.Equal(t, "1.2345678901234567", store.valToString(1.234567890123456789))
+	assert.Equal(t, "200000.0", store.valToString(2E5))
+	assert.Equal(t, "-2E+10", store.valToString(-2E10))
+	assert.Equal(t, "2E-10", store.valToString(2E-10))
+	assert.Equal(t, "1.2345E+100", store.valToString(1.2345E100))
+	assert.Equal(t, "1.2345E-100", store.valToString(1.2345E-100))
 	assert.Equal(t, "true", store.valToString(true))
 	assert.Equal(t, "false", store.valToString(false))
 	ts, _ := time.Parse(time.RFC3339, "2025-01-02T03:04:05Z")