Leave the front-matter values that would be bigints as strings

ox-hugo.el

@@ -2411,14 +2411,21 @@ Optional argument FORMAT can be \"toml\" or \"yaml\"."
                  (string= (substring val -1) "\"")) ;Last char is literally a "
             (and prefer-no-quotes ;If quotes are not preferred and `val' is only alpha-numeric
                  (string-match-p "\\`[a-zA-Z0-9]+\\'" val))
+            ;; or if it an integer that can be stored in the system as
+            ;; a fixnum.  For example, if `val' is
+            ;; "10040216507682529280" that needs more than 64 bits to
+            ;; be stored as a signed integer, it will be automatically
+            ;; stored as a float.  So (integerp (string-to-number
+            ;; val)) will return nil.
+            ;; https://github.com/toml-lang/toml#integer Integer
+            ;; examples: 7, +7, -7, 7_000
+            (and (string-match-p "\\`[+-]?[[:digit:]_]+\\'" val)
+                 (integerp (string-to-number val)))
             (string= "true" val)
             (string= "false" val)
             ;; or if it is a date (date, publishDate, expiryDate, lastmod)
             (string-match-p org-hugo--date-time-regexp val)
-            ;; or if it is any number (integer or float)
-            ;; https://github.com/toml-lang/toml#integer
-            ;; Integer examples: 7, +7, -7, 7_000
-            (string-match-p "\\`[+-]?[[:digit:]_]+\\'" val)
+            ;; or if it is a float
             ;; https://github.com/toml-lang/toml#float
             ;; Float examples (decimals): 7.8, +7.8, -7.8
             (string-match-p "\\`[+-]?[[:digit:]_]+\\.[[:digit:]_]+\\'" val)

test/site/content-org/all-posts.org

@@ -1774,6 +1774,24 @@ Custom TOML front-matter with TOML tables.
 Custom YAML front-matter with nested maps.
 #+end_description
 {{{oxhugoissue(139)}}}
+** Front-matter values with BigInts                             :bigint:toml:
+:PROPERTIES:
+:EXPORT_FILE_NAME: front-matter-bigint-value
+:EXPORT_HUGO_CUSTOM_FRONT_MATTER: :small_int "234" :big_int "10040216507682529280"
+:END:
+#+begin_description
+Test that front-matter values that are integers represented as
+strings, but cannot be stored as 64-bit signed integers are
+left as strings.
+#+end_description
+
+In this test, the small integer "234" (i.e. the one that can be
+represented as a 64-bit signed integer) is saved as an integer in the
+TOML front-matter.
+
+But the big integer "10040216507682529280" which would need more than
+64-bits to be stored as a signed integer is left as a string in the
+TOML front-matter.
 * Resources                                                       :resources:
 ** TOML                                                                :toml:
 *** Post with resources in front-matter (TOML)

test/site/content/posts/front-matter-bigint-value.md

@@ -0,0 +1,20 @@
++++
+title = "Front-matter values with BigInts"
+description = """
+  Test that front-matter values that are integers represented as
+  strings, but cannot be stored as 64-bit signed integers are
+  left as strings.
+  """
+tags = ["custom-fm", "bigint", "toml"]
+draft = false
+small_int = 234
+big_int = "10040216507682529280"
++++
+
+In this test, the small integer "234" (i.e. the one that can be
+represented as a 64-bit signed integer) is saved as an integer in the
+TOML front-matter.
+
+But the big integer "10040216507682529280" which would need more than
+64-bits to be stored as a signed integer is left as a string in the
+TOML front-matter.